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Abstract

Assessment of ago-morphological diversity among conserved accessions is helpful in germplasm management and crop improvement practices. In this study 174 Pakistani Rice landrace genotypes were evaluated for 18 quantitative and 9 qualitative agro-morphological traits. Substantial amount of genetic diversity was observed for most of the traits studied. Mean values of landrace genotypes were compared with three check varieties, IR36, Super Basmati and JP5.

Introduction

Rice is grown in all four provinces of Pakistan. However, the acreage under rice varies greatly from one province to another. The Punjab and Sindh are the major rice growing provinces with about 59% and 33%, respectively of the total rice in the country. The remaining 5% of the area is planted in Baulochistan and 3% in NWFP (FAO, 2004). Despite the fact that it’s cultivated area is far smaller than wheat (more than 7.24 million), it has a great impact on national economy due to two reasons. Firstly, rice is the only crop which can be grown successfully in vast chunks of salt-ridden and water-logged areas where it facilitates not only the reclamation of land for the cultivation of other crops but also provide food. Secondly, superior quality basmati has a consistently increasing demand in the foreign countries. Consequently, there is a great scope for augmenting the foreign exchange earning by exporting it in bigger quantity. In view of these facts, it is highly desirable to increase the production and improve the quality of rice. The quality is particularly more important from the “trade view point”, as it is instrument entail in increasing and then sustaining the demand in the foreign market in competition with other rising exporting countries. There in no denying the fact that purity is the very sole of quality. The impurities not only restrict the export trade, but also inflict losses to the growers, millers and the consumers alike. Therefore, these should possibly be minimized (Salim et al. 2003).

Rice (Oryza sativa (2n = 24) is a monocot plant and belongs to the Poaceae family and Oryzoidea subfamily. It occupies almost one-fifth of the total land area under world cereals. It covers about 148 million hectares annually that is roughly 11 percent of the world-cultivated land. It is life for more than half of humanity and in past, it shaped the cultures, diets, and economies of billions of people in the world (Farooq et al. 2009). Rice is a major source of macro and micronutrients for human being. It is used as feed for more than two billion people worldwide and one of the staple food in Asia. It provides over 21 percent of the calorific needs of the world's population and up to 76 percent of the calorific intake of the population of South East Asia (Fitzgerald et al. 2009). Depending upon the irrigation water availability, rice can be grown in any part of the country from sea level up to 2500m height. Pakistan has a climate and a potential in soil that permits the expectations of a most bright future for the production of rice. Considering temperature difference, optimum sowing seasons and the varietal performance, rice growing areas can be divided in four ecological zones (Salim et al. 2003). Introgression of genes from other rice species can provide genetic variation to improve rice and meet the challenges affecting rice production. Morphological traits including both qualitative and quantitative ones are used to evaluate genetic relationship among genotypes (Goodman 1972; Bajracharya et al. 2006). Agronomic evaluation was used for screening of lines with desired performance by Akram et al. (1995) in field leading to the identification of varieties possessing longer and fine grains as donors for utilization in breeding programs aimed for the improvement of grain length in Basmati rice. The interrelations among grain quality traits could be useful to study the relationship among grain quality components and for improving selection criteria (Koutroubas et al. 2004).

Keeping in view these benefits, morphological variation is a selection criterion for plant scientists among landrace genotypes. Though the environmental factors also play an important role in morphological variation but the knowledge of agro-morphological diversity and the distribution pattern of variation among crop species could be an invaluable aid in germplasm management and crop improvement strategies. Zeng et al. (2007) studied genetic diversity based on ecogeographic location and morphological characters of rice landraces (Oryza sativa L.) in Yunnan, China. Major difference in ecological diversity index of rice resources between prefectures or counties in Yunnan province exists. Sanni et al. (2008) studied the relationship in geographical pattern and morphological variation of 880 rice landrace in Coˆte d’Ivoire for 13 agro-morphological characters. Result of the phenotypic frequency showed differential distribution of landraces with height, heading and maturity period which reflected the distribution pattern of different Oryza sativa landraces in Coˆte d’Ivoire that proved useful in germplasm management and breeding programs.

Morpho-physiological traits are an important tool in hands of plant breeders for identification and purity testing of rice varieties. Present study is based upon the morphological evaluation of Pakistani rice landraces using quantitative and qualitative traits as marker. The purpose of the study is to evaluate geographical pattern of diversity, regional estimation of phenotype polymorphism and selection of better genotype for use in breeding programs.

Materials and Methods

Plant Materials

Rice genotypes used in this study consisted of 174 landraces from all four ecological rice growing zones collected in 1974 in a germplasm collection project. Collections include three major rice growing provinces Punjab, Sindh and NWFP (North West Frontier Province) of Pakistan where is used as second major crop after wheat. These germplasm accessions have been preserved ex-situ in gene bank of NARC (National Agricultural Research Centre), Islamabad.

Experiment Location

The experiments were conducted during growing seasons 2006 and 2007 under field condition at Institute of Agro-biotechnology and Genetic Resources, National Agricultural Research Institute, Islamabad (33.40º N and 73.07º E) approximately at an altitude of 518meters above sea level.

Experimental Design and Crop Management

A nursery was raised in pots and then transplanted into field. Rice field was grown in an augmented design with three check varieties (IR6, Super-basmati and JP5) during 2006 and 2007. Data was recorded on the 18 quantitative traits (days to 50% heading, days to maturity, flag leaf length, flag leaf width, flag leaf area, plant height, panicle length, total tillers per plant, productive tiller per plant, branches per panicle, grain yield per plant, 1000 grain weight, straw yield per plant, Harvest index, paddy grain length, paddy grain breadth and grain length to breadth ratio) and nine qualitative traits (Flag leaf angle, flag leaf shape, flag leaf appearance, lodging, panicle type, panicle exertion, awning, awn color and seed coat color) for 2006 and 2007 respectively.

Statistical Analysis

The mean value of each character for all accession was calculated and subjected to statistical analysis i.e., Standard deviation, variance, standard error and correlation coefficient, using statistical software, Microsoft Excel and STATISTICA. The Shannon-Weaver diversity index (H0) using Jain et al. (1975) was calculated by analysing phenotypic frequencies of the 18 quantitative traits during both years for collective as well as provincial groups. Multivariate analysis was performed using NTSYS PC2.2, Euclidean distance was estimated based on quantitative a well as qualitative traits data (Nei, 1987) and based on distance matrix, dendrograms were constructed for both years using un-weighted paired group arithmetic means. Second multivariate analysis, the principle component analysis (PCA) was also done in order to identify the traits with maximum contribution in total diversity.

Results

Collective phenotypic response during two experimental years

All eighteen traits were polymorphic and almost same trend was observed during both growing seasons on whole germplasm accessions. Table ?? shows the frequency distribution for 18 quantitative trait as percentage of the total number of accessions used in study. Majority of the landraces were early in flowering and maturity with medium flag leaf length during year 2006 and 2007. 72.3% and 67.2% of the landraces during 2006 and 2007, respectively were tall in height. Maximum accessions produced 10 to 15 productive tillers per plant. Allele for intermediate panicle length was dominant in Pakistani landrace genotypes during both field trials. Majority of the accessions showed vary high (80%) seed setting percentage during both years. Grain yield and biological yield showed not considerable consistency in continuos field trials. Intermediate grain length and width was observed in majority of the landraces during both years.

Patterns of phenotypic variation in Punjab, Sindh and North West Frintier Province

The individual characters, differs in their patterns of distribution as well as the amount of variation. Table 3 shows the frequency distribution for individual characters as the percentage of the number of accessions from each geographical zone. The largest amount of entries was from the Punjab and was represented by 153 accessions, followed by North West Frontier province with 11 accessions and 10 accessions from Sindh respectively

Generally, paddy grain breadth was relatively monomorphic for Sindh province (zone III and IV) as only broad grain breadth was observed in this province while it was polymorphic in other zones. Remaining quantitative traits were highly polymorphic in all rice growing zones of Pakistan. Seventy two percent of the landraces in the whole germplasm collection were found to be tall in the regions, 26% were of moderate height while only 1% were semi dwarf. The collection had predominantly medium leaves of average length and this distribution pattern was almost the same in all the regions. Forty nine percent of the landraces had relatively wide leaves, short as 37 % and while only 10 % with narrow leaf structure. The leaf length, leaf blade pubescence and leaf angle were widely distributed throughout the collection. The Phenotypic distribution of the leaf length showed that, 72% had intermediate, while those with relatively longer and shorter leaves were 19 and 10% respectively. Leaf blade pubescence and leaf angle were widely distributed throughout the collection. The phenotypic distribution for the number of days to 50% head did not follow the same pattern in all the zones. In the northern and north-western region, the accessions that headed early were more than the late heading type, in the west-central most of the accession fell into the intermediate number of days to 50% heading while in the west, there more of the late maturing accessions than the early heading varieties.

Degree of abundance for qualitative traits

The most abundant or maximum values for each qualitative trait were observed in rice genotypes to check degree of abundance for different traits. The trait of flag leaf angle showed maximum value as ‘Erect leaf’ in 66 genotypes with frequency of 37.3%. In 87 genotypes lodging was ‘slightly present’ with frequency of 49.1%. Panicle type was observed ‘compact’ in 81 genotypes with frequency of 45.8%. Panicle exertion was ‘well exerted’ in abundance with frequency 91 and frequency percentage 51.4%. Most of the genotypes were seen ‘awned’ during observation of awning trait with frequency 93 and percentage 52.5%. The character of awn color was also dominated by white with frequency 114 and frequency percentage 64.4%. ‘Dark brown’ seed coat color was most abundant of all with frequency 65 and frequency percentage 36.7%.

Correlation coefficient analysis:

The correlation coefficients among the quantitative traits (Table 2) revealed that the days to heading and days to maturity showed strongly positive significant correlation with each other was positively correlated with all the other traits except the 100 seeds weight which was negatively correlated with number of seeds per pod. After keen observation of all the traits and using different statistical analysis, the best performance and genetically diverse gene pools were selected (Table 3) for developing improved genotypes. Days to heading and days to maturity showed strongly positive significant correlation with each other, in addition to branches per panicle, paddy grain length and grain length to breadth ratio. A strongly positive and significant correlation was observed between plant height and flag leaf length as well as panicle length. Grain yield per plant was also strongly positively related with productive tiller per plant. Highly significant and negative correlations were observed for days to heading and maturity and flag leaf breadth. Flag leaf breadth also showed highly significant negative correlation with productive tillers per plant, paddy grain length as well as with grain length to breadth ratio. Paddy grain breadth showed highly significant negative correlation with paddy grain length and grain length to breadth ratio as well.

Estimates and analysis of Diversity indices

Shannon-Weaver diversity index (H0) for 18 quantitative traits was measured separately for different geographical zones and ecological regions and appropriately weighted by the number of accessions. H0 was estimated for each of the 18 characters in three geographical rice growing zones. The mean of Shannon diversity index, pooled over characters within geographical regions, varied from 0.68 for Punjab to 0.61 for Sindh and 0.57 for NWFP during 2006 while in next year 2007, it was 0.60 for Punjab, 0.62 for Sindh and 0.67 for NWFP. For all the collected landraces, no diversity was observed in grain breadth of accessions collected from Sindh province, the minimum value of H0 was 0.20 for 1000GW and paddy grain length to breadth ratio of accessions collected from NWFP during 2006 while it showed a little increased in next growing season. Collections from Punjab showed least diversity in panicle length during both years and days to heading showed minimum diversity in accessions collected from Sindh. The maximum value was 1.00 for the trait days to heading in accessions collected from Punjab, with an overall mean of 0.47. Variation was not consistent among all studied quantitative variables. However, the mean of H0 showed an apparent diversity for all characters, considering the values of the pooled over characters within each classifying variable. The results of analysis of variance (ANOVA) in Table 5 showed significant differences for between characters within geographical zones and ecological regions. Significant differences for both geographical zones and ecological regions existed only in the leaf blade pubescence. Awning showed significant difference between ecological zones. 1000-grain weight revealed significant difference between geographical regions.

Multivariate Analysis Based on Agro-morphological Traits

Twenty seven agro-morphological traits were analyzed by multivariate analyses using two complementary procedures, namely, cluster and principal component analyses (Sneath and Sokal, 1973). To avoid effects due to scaling differences, means of each trait were standardized prior to analyses. Euclidean dissimilarity coefficient matrices were used to reveal the patterns of genetic relationship between genotypes with a cluster analysis performed by NTSYS-pc, Version 2.1 package (Rohlf, 2005). The results are presented in the form of phenograms to depict and evaluate the degree of morphological similarity and to infer relationships among genotypes.

Estimation of Euclidean distance

The Euclidean distance matrix for all 15,487 pair-wise comparisons of 174 landraces was beyond the scope of its presentation in tabulated form. However, a wide range of genetic distance was observed among the landraces tested. The estimates of Euclidean genetic distance values ranged from 1.9 (between 6655 and 6658) to 14.8 (between 6779 and 6757) during 2006, followed by 12.3, 12.2 and 12.1 observed between 6779 and check variety Super basmati, 6779 and 6556, 6546 and 6757, respectively. The mean genetic distance between all pairs of landraces was 7.02±1.07. Landraces 6779, 6758, 6624, 6745, 6628 and 6626 showed maximum distance with all other landraces. It was observed that Euclidean distance among clusters ranged from 1.09 (cluster-I and cluster-V) to 8.94 (cluster-IV and cluster-V) in germplasm landraces during 2006. During 2007 Euclidean dissimilarity estimates among 174 landraces ranged between 1.7 and 15.1. The average Euclidean distance between all pairs of landraces was 8.45±0.69. Landraces 6658 and 6646 were the closest germplasm landraces, with a distance of 1.7, 6770 and 6757 showed the maximum similarity. It was followed by Euclidean distance of 14.6, 14.0, 13.2and 13.1 recorded in 6546 and 6758, 6757 and 6779, 6546 and 6624, and check variety IR6 and 6779, respectively. Euclidean distance among clusters ranged from 2.77 (cluster-I and cluster-II) to 9.01 (cluster-IV and cluster-V).

Cluster analysis

Cluster analysis based on 27 morphological variables divided 174 landraces in to five main clusters (I, to V) at dissimilarity coefficient value of 11.4 during both growing seasons. The dendrogram was constructed using complete linkage method. Cluster-I consisted of major rice landraces (134 landraces), early in heading (72±10.8), as well as maturity (116.1±13.5), with medium grain yield potential (30.7±7.7) and highest biological yield per plant (184.9±58.4). Cluster-II comprised of twelve landraces which were characterized as early maturing (113.8±13.6 days), long stature (142.9±21.6 cm), with more flag leaf area (57.0±21.5), bearing maximum number of total (24.3±5.4) as well as productive (21.4±4.6) tillers per plant, maximum harvest index (0.3±0.1), higher grain yield per plant (41.3±13.3) and minimum grain length (7.2±0.4) and gain length to width ratio (2.5±0.5). This group, also include japonica type check variety “JP5”. Majority of the landraces in this group belong to North West Frontier Province. Cluster-III included 15 landraces, earliest in heading (79.8±11.9) and maturity (120.9±14.5) with medium height (153.6±22.0), medium panicle size (27.8±3.6), lower biological yield (176.0±51.9), maximum harvest index, highest grain yield per plant (43.5±11.2) and slender grain length to breadth ratio (4.0±0.8). Cluster-IV also consists of fifteen landraces respectively with early heading (67.7±6.4), and maturity (107.2±9.1), shortest length of panicles (22.9±3.1), lowest garin yield(82.5±8.6) and seed setting percentage(27.0±5.6) while cluster-V consists of only one accession early in heading(64 days) as well as maturity(109 days) with long stature(183cm),maximum grain length and length to breadth ratio. In 2007, on the basis of Euclidean distance, dendrogram recovered the five main clusters as in 2006. The main differences existed in the fragmentation of various clusters and their arrangement. Cluster-I consisted of major rice landraces (70 landraces), early in heading (70.7±10.4days), as well as maturity (113.8±12.0days), tall plant height(159.8±11.3cm), maximum seed setting percentage(85.1±5.7), Harvest index(0.2±0.1) and 1000-grain weight (28.8±10.7g) and medium grain length (8.4±0.7mm).Cluster-II comprised of seventy five landraces which were characterized as very early in heading (65.6±8.1days) and maturity (106.7±9.2days), higher harvest index (0.2±0.0), taller plant height (152.8±13.8cm), medium grain yield (27.7±8.1g). Cluster-III included 24 landraces very late in days to heading(85.3±10.2days) and maturity(132.8±9.3days), maximum biological yield per plant (268.4±61.7g), minimum grain yield per plant (27.4±7.0 g).Cluster-IV also consists of fifteen landraces respectively with minimum flag leaf area (31.4±4.5cm2), shortest plant height (117.5±25.1cm), maximum productive tillers per plant(23.9±6.7), minimum paddy grain length to width ratio(3.4±1.0) and lowest panicle length(23.0±2.2cm) While cluster-V consists of only two landraces having maximum flag leaf area(92.9±50.4cm2), plant height(172.6±14.7cm), panicle length(30.6±3.4cm), paddy grain length(9.1±0.0mm), grain yield per plant(33.2±8.3g), biological yield per plant (210.0±28.3g) and paddy grain length to width ratio(4.5±0.6) .

Principal Component Analysis

In order to assess patterns of variation, principal component analysis was done for 177 rice landraces by considering all the variables simultaneously during both years. It was observed that six of the 18 principal components (PCs) with an Eigen value higher than 1.0, accounted for 72.09 percent of the total variability amongst the 177 landraces evaluated during 2006. The coefficients defining six principal components of these data are given in Table >???. These coefficients were scaled, so that they present correlations between observed variables and derived components. The first principal component had 21.04percent of the total variation in the morphological traits. Days to heading(0.358), days to maturity(0.388),grain length/breadth ratio(0.306), paddy grain length(0.206), branches per panicle (0.142), biological yield per plant(0.266), plant height(0.120) and total tiller per plant(0.199) contributed primarily in variation. Conversely flag leaf length(-0.138), flag leaf width(-0.337), flag leaf area(-0.303), harvest index(-0.149), 1000grain weight(-0.057) and paddy grain breadth(-0.233) had all negative weights. In year 2007, six of 19 components with >1.0 eigenvalues, contributed 70.48percent of the total variability found in germplasm landraces (Table ???). Principal component 1 contributed 19.17percent, whereas PC2, PC3, PC4, PC5 and PC6 contributed 13.84percent, 12.82percent, 10.53percent, 8.03percent and 6.11percent, respectively in total divergence (Table ????). The first principal component depicted primarily the pattern of variations in days to heading(0.374), days to maturity(0.398), plant height(0.076), total tiller per plant(0.212), productive tiller per plant(0.148), panicle length(0.170), branches per panicle(0.148), seed setting percentage(0.002), grain yield per plant(0.121), biological yield per plant(0.274), paddy grain length(0.352) and grain length breadth ratio (0.367) . On the contrary, flag leaf length (-0.123), flag leaf width (-0.280), flag leaf area (-0.234), harvest index (-0.043), 1000-grain weight (-0.026) and paddy grain breadth (-0.282) had all negative weights.

Grain length to breadth ratio, a selection criterion

Grain length to breadth ratio is a quality measure for rice and not as much sensitive to environmental fluctuations as other agronomic traits. The germplasm is divided into three major groups; long, short and medium. Along with other desirable traits on the basis of seed length to breadth ratio, landraces with long grain took longer time to maturity during both years, while short grained landraces took lower time for heading and maturity during both years. Long grained landraces have smaller leaf area during both years than short grained landraces having larger leaf area. Short grained landraces showed largest harvest index during 2006 and 2007. Percentage of medium grained genotypes among Pakistani landraces was highest (43% in 2006 and 46% in 2007) during both growing years. On the basis of consistent field performance during 2006 and 2007 for some quantitative traits, a group of landraces was selected (Table ????).

Discussion

Genetic diversity of crop landraces requires every aspect of the diversity to be explored. It is necessary to mine new genes for crop improvement (Iannetta et al., 2007). Conservation of the genetic diversity of landrace crops is an important issue because of the extent to which this diversity is declining after green revolution. In order to maintain, evaluate and effectively utilize germplasm, extent of genetic diversity must be measured. Only source of genetic diversity is the germplasm by which the plant breeders develop new cultivars (Baranger, 2004). As the qualitative traits are under genetic control of two or many alleles of a single gene with little or no environmental modifications to obscure the gene effects e.g seed colour, seed shape, awning, awn colour etc, so no considerable change was observed in qualitative traits in next growing season. Quantitative traits are economically important; those have high variability because they are also controlled by more than one gene and could be used for the crop improvement (Amurrio et al., 1995; Fall et al., 2003). In Pakistani rice landraces, basic statistics for both 2006 and 2007 showed high degree of variation for all these 18 quantitative traits.These traits are directly or indirectly yield contributing and genetically very important for the selection of high yielding genotypes. Days to heading in one study on Bangladesh rice landraces ranged from 78 days to 109 days (Bisne and Sarawgi 2008). The variation for days to heading and maturity may be attributed to seasonal variations. Shah et al. (1999) stated that the opening of the spikelet depends primarily on the prevailing atmospheric temperature, the light intensity and other climatic conditions. Flag leaf area with its angle is the most important character in which maximum photosynthesis is occurred. Flag leaf area has the maximum contribution towards grain yield.

Compared with commercial varieties, landrace genotypes were relatively taller in size than commercial cultivars. This is a typical feature of landraces, which excel in their capacity to support panicle growth by large stem reserve mobilization. Few short statured lines were identified which can be further utilized to develop fertilizer responsive and lodging resistant rice varieties. Leaf length and width are also important traits to be considered because of its contribution in photosynthetic activities. A larger leaf area development at early growth stage is thought to be a desirable character for better stand establishment, which ultimately affect the yield level. In this germplasm, 7 accessions were identified with leaf area more than 85cm square. The 1000 Grain weight is one of the most important yield components. Overall 18 accessions were selected having more than 40g weight during both years. These line scan be utilized as parents to improve seed weight which ultimately increase the yield level. Most of the positive associations do not affect yield in this environment, the reason behind this is unknown. Highly positive correlations were also between heading and maturity time, paddy grain length and paddy grain length width ratio, flag leaf size and plant height. There was also significant positive association between grain yield and its component traits such as, total tiller per plant, productive tiller per plant, etc. It was also observed that landraces from northern hilly areas e.g Swat and Malakand, possess smaller and broad grains. This may attribute to the fact that grain length decreases with increase in altitude (Siddiqui et al., 2007). Though the grain length decreased in high altitude the increase in width compensated for grain volume to accumulate the grain weight, as it showed an increasing trend with increase in altitude, though other factors are also involved in the grain filling. These results suggest that Pakistan rice cultivars possess a distinct correlation in terms of altitudinal distribution for grain morphology.

Days to heading and panicle length showed high polymorphism in Punjab collection while it was comparatively lower in Sindh and NWFP province. The reasons for this difference may be the lower sample size from Sindh and NWFP, which may be due to a narrow genetic background due to population food preferences, farmer choice and domestication of only few rice varieties with specific traits. Major programs for rice improvement done on behalf of Punjab this may be the reason for large collections with broad genetic background are available here.

Different clustering analyses and PCAs scattered plot revealed that there is a lot of genetic diversity among the studied genotypes and also found that quantitative traits can also be used as a maker in breeding program but there was no geographic association because the genotypes from one place enter into more than one clusters. Conversely, genotypes from different geographic origins were relatively unique and tend to be clustered as was determined not only by environmental difference but also by genetic factors. Although principal component analysis grouped genotypes together with greater morphological similarities, the clusters did not necessarily include all the landraces from the same or nearby sites. The landraces were grouped according to their morphological similarity and not due to geographical origin. Gupta et al. (1991) reported that genetic diversity in mustard was not related to geographical distribution of the germplasm, as lines from different geographic regions were pooled in the same cluster. Similarly, Amurrio et al. (1995) observed that grouping patterns of pea landraces did not reflect geographical origin.

Overall our results showed that rice landraces explored from Pakistan harbour a broad range of genetic variation. From the present study, a number of promising lines have been identified for specific traits that may have some potential value in rice breeding programs.

Table : Principal components for morpho-physiological traits of Pakistani rice landrace during 2006 and 2007

Trait

PC1

PC2

PC3

PC4

PC5

PC6

PC1

PC2

PC3

PC4

PC5

PC6

Eigenvalue

3.79

2.57

2.17

1.81

1.5

1.15

3.45

2.49

2.31

1.89

1.44

1.1

Cumulative eigenvalue

3.79

6.36

8.52

10.33

11.83

12.98

3.45

5.94

8.25

10.14

11.59

12.69

Proportion of variance

21.04

14.28

12.03

10.05

8.31

6.38

19.17

13.84

12.82

10.53

8.03

6.11

Cumulative variance

21.04

35.32

47.35

57.4

65.71

72.09

19.17

33.01

45.83

56.35

64.38

70.48

Eigenvectors(2006)

Eigenvectors(2007)

DH

0.358

0.067

0.198

0.015

0.288

-0.016

0.374

-0.177

0.112

-0.099

-0.317

0.044

DM

0.388

0.011

0.204

0.121

0.233

-0.076

0.398

-0.183

0.03

-0.191

-0.252

0.084

FLL

-0.138

-0.189

0.378

-0.299

-0.314

0.073

-0.123

-0.462

-0.105

0.143

0.248

0.156

FLW

-0.337

-0.096

0.203

-0.07

0.11

-0.258

-0.28

-0.297

-0.131

0.075

-0.116

-0.039

FLA

-0.303

-0.183

0.394

-0.256

-0.153

-0.125

-0.234

-0.503

-0.142

0.147

0.118

0.087

PH

0.12

-0.196

0.408

-0.145

-0.04

0.353

0.076

-0.411

-0.142

-0.01

0.087

-0.139

TT/P

0.199

0.428

0.072

-0.083

-0.438

-0.05

0.212

-0.071

0.426

-0.084

0.385

0.042

PT/P

0.212

0.437

0.063

-0.056

-0.413

-0.053

0.148

-0.076

0.443

-0.02

0.434

0.061

PL

0.206

0.009

0.158

-0.057

-0.065

0.467

0.17

-0.188

0.076

0.001

0.173

-0.459

B/P

0.142

0.021

0.305

-0.01

0.319

-0.012

0.148

-0.261

-0.07

-0.056

-0.281

-0.193

SS(percent)

0.058

0.117

0.076

-0.299

0.322

-0.348

0.002

-0.036

0.129

0.16

-0.338

0.508

GY/P

0.034

0.304

0.047

-0.446

0.245

0.067

0.121

-0.127

0.331

0.433

-0.239

-0.164

BY/P

0.266

-0.064

0.292

0.217

-0.046

-0.196

0.274

-0.184

-0.025

-0.329

-0.07

0.037

HI

-0.149

0.309

-0.177

-0.466

0.213

0.203

-0.043

0.014

0.322

0.571

-0.179

-0.173

1000GW

-0.057

-0.077

-0.075

0.098

0.145

0.58

-0.026

0.126

-0.135

-0.034

-0.073

-0.593

GL

0.293

-0.293

-0.12

-0.209

-0.054

-0.084

0.352

0.004

-0.291

0.194

0.053

0.013

GB

-0.233

0.311

0.279

0.298

0.122

0.049

-0.282

-0.137

0.302

-0.33

-0.224

-0.102

GL/GB

0.306

-0.331

-0.253

-0.309

-0.096

-0.084

0.367

0.106

-0.325

0.316

0.167

0.083

Table: Basic Statistics for 177 Pakistani rice landraces for 18 quantitative traits in 2006 and 2007

Year-2006

Year-2007

Trait

Mean±SE

Min

Max

CV(%)

Variance

Mean±SE

Min

Max

CV(%)

Variance

DH

72.4±0.81

48

99

14.9

117.0

70.4±0.85

43

97

15.8

129.3

DM

115.7±1.01

85

145

11.6

179.8

113.2±1.02

80

145

11.9

184.5

FLL

45.5±0.60

29.2

72.0

17.6

64.2

44.3±0.67

21.5

79.3

20.0

78.5

FLW

1.8±0.02

1.3

2.6

15.8

0.1

1.7±0.02

1.1

2.5

14.9

0.1

FLA

63.2±1.2

33.3

130.2

25.7

263.2

58.3±1.20

26.2

128.6

27.5

257.0

PH

156.9±1.11

92.4

198.6

9.4

216.4

156.0±1.09

93.0

187.0

9.3

211.6

TT/P

16.6±0.32

10.4

36.5

25.8

18.2

15.3±0.34

8.6

35.2

29.8

20.7

PT/P

14.1±0.30

8.2

30.5

28.5

16.2

13.6±0.31

7.9

32.0

30.3

16.9

PL

26.8±0.28

13.3

47.7

14.0

14.1

24.9±0.32

12.4

48.5

17.0

18.0

B/P

14.7±0.28

9.6

34.2

25.6

14.3

13.1±0.36

7.4

35.6

36.6

22.8

SS%

83.1±0.49

63.0

93.0

7.8

42.2

83.9±0.50

58.6

99.9

7.9

44.2

GY/P

32.3±0.71

16.4

70.1

29.3

89.5

29.2±0.76

8.9

66.8

34. 4

101.0

BY/P

180.1±4.36

100

380

32.2

3370.5

200.3±4.11

120

390

27.3

2984.7

HI

0.20±0.01

0.05

0.63

41.6

0.01

0.15±0.00

0.03

0.44

40.3

0.00

1000GW

27.1±0.72

13.7

60.9

35.2

91.1

27.1±0.76

12.6

63.6

37.2

101.4

PGL

8.5±0.06

6.4

10.4

9.5

0.65

8.4±0.06

6.6

10.1

9.2

0.59

PGB

2.3±0.03

1.6

3.2

15.2

0.12

2.3±0.03

1.7

3.3

14.8

0.12

GL/GB

3.8±0.05

2.1

5.9

19.1

0.52

3.7±0.05

2.2

5.2

18.3

0.45

Table: Association of grain characteristics with other quantitative traits in Pakistani rice germplasm

Range groups (Year 2006)

Range groups (Year 2007)

Traits

Short

Medium

Long

Short

Medium

Long

DH

70.82±1.75

71.34±1.06

73.67±1.46

67.63±1.63

69.12±1.03

72.60±1.67

DM

111.92±2.38

115.3±1.46

117.33±1.65

108.16±2.09

112.53±1.34

116.19±1.88

FLL

45.41±1.92

46.05±0.77

45.48±0.98

44.32±1.97

45.37±0.81

43.50±1.16

FLW

1.99±0.06

1.82±0.03

1.75±0.03

1.85±0.04

1.72±0.02

1.67±0.03

FLA

69.45±4.08

63.90±1.58

60.95±1.83

62.81±3.19

59.73±1.56

55.62±2.09

PH

153.70±2.38

158.18±1.52

158.72±1.66

152.35±2.17

159.10±1.51

155.88±1.66

TT/P

17.56±1.24

16.35±0.41

16.38±0.46

15.65±1.12

14.84±0.40

15.58±0.60

PT/P

15.02±1.11

13.85±0.39

13.93±0.45

14.46±1.03

13.19±0.37

13.53±0.52

PL

25.41±0.63

26.96±0.41

27.37±0.46

23.5±0.55

25.38±0.46

25.19±0.58

B/P

14.80±0.52

15.20±0.43

14.19±0.48

12.29±0.5

13.19±0.41

13.23±0.82

SS(%)

83.03±1.33

82.2±0.76

83.87±0.73

84.37±1.31

83.72±0.70

83.91±0.87

GY/P

33.64±2.22

31.13±0.98

32.88±1.12

28.53±2.09

28.13±1.02

30.77±1.31

BY/P

170.71±11.61

181.06±6.64

183.38±6.93

185.5±8.53

198.7±6.19

210±7.08

HI

0.22±0.02

0.18±0.01

0.19±0.01

0.16±0.01

0.15±0.01

0.15±0.01

1000GW

28.86±2.11

25.80±1.09

27.88±1.06

27.02±1.77

26.34±1.13

28.07±1.30

GL

7.34±0.12

8.41±0.07

8.92±0.06

7.19±0.05

8.47±0.06

8.80±0.06

GB

2.86±0.05

2.33±0.02

2.04±0.01

2.91±0.03

2.33±0.02

2.06±0.01

GL/GB

2.61±0.10

3.62±0.03

4.37±0.03

2.48±0.04

3.63±0.02

4.26±0.02

No. of Landraces

28

75

71

30

81

63

Table-3: Selected germplasm accessions of local rice on the basis of best performance in important agro-morphological and grain characteristics during growing seasons 2006 and 2007

Trait

Range

Accessions Identified

Days to maturity

< 100 days

6560, 6570, 6621, 6655, 6675, 6685, 6731, 6734, 6746, 6746, 6754,6755, 6756, 6757, 6758

Flag leaf size/area

> 85 cm2

6595, 6542, 6629, 6636, 6724, 6725, 6779

Plant height

<130 cm

6564, 6626, 6680

Productive tillers/plant

> 20 tillers

6527, 6550, 6551, 6556, 6557, 6558, 6623, 6624, 6626, 6738, 6744, 6754, 6757, 6758

Panicle length

> 30 cm

6524, 6537, 6538, 6562, 6563, 6565, 6569, 6590, 6744, 6760, 6779

Spikelets /panicle

> 18 spike-lets

6526, 6527, 6550, 6556, 6557, 6558, 6564, 6623, 6624, 6626, 6629, 6731, 6738, 6744, 6757, 6758

Grain yield/plant

> 40 g

6520, 6523, 6550, 6559, 6559, 6585, 6620, 6623, 6624, 6628, 6633, 6645, 6651, 6654, 6683, 6712, 6755

1000-grain weight

> 40 g

6506, 6522, 6525, 6538, 6547, 6581,6615 ,6645, 6651, 6666, 6667, 6668, 6675, 6676, 6771, 6672, 6672, 6720

Grain length

˃ 10 mm

6505

9

Traits

DF

DM

PH

PL

FLL

FLW

LA

TT/P

PT/P

SS%

BY/P

GL

GW

HI

B/P

GL/GB

1000GW

GY/P

2006

0.70

1.18

0.14

0.65

0.73

0.63

1.28

1.10

0.66

1.37

1.30

0.91

0.72

1.13

0.72

0.47

0.72

1.30

2007

0.65

1.35

0.14

0.77

0.80

0.70

1.16

1.10

0.74

1.33

1.46

0.79

0.62

0.93

0.52

0.52

0.79

1.33

PUNJAB

DH

DM

FLL

FLW

FLA

PH

GY/P

B/P

SS%

PL

PTP

TTP

BY/P

HI

1000GW

GL

GB

GL/GB

Mean±SE

2006

1.00

0.96

0.52

0.74

0.56

0.43

0.92

0.52

0.99

0.38

0.79

0.49

0.90

0.91

0.51

0.56

0.44

0.76

0.68±0.05

2007

1.00

0.85

0.53

0.63

0.53

0.44

0.88

0.33

0.83

0.35

0.75

0.73

0.97

0.25

0.53

0.48

0.38

0.37

0.60±0.05

SINDH

2006

0.32

0.50

0.63

0.80

0.80

0.50

0.94

0.32

0.94

0.50

0.64

0.32

0.94

0.50

0.89

0.50

0.00

0.90

0.61±0.06

2007

0.27

0.42

0.53

0.79

0.54

0.51

0.86

0.54

1.00

0.42

0.54

0.51

0.97

1.00

0.75

0.67

0.00

0.92

0.62±0.05

NWFP

2006

0.89

0.50

0.50

0.68

0.60

0.44

1.00

0.43

0.62

0.40

0.82

0.82

0.82

0.68

0.20

0.38

0.38

0.20

0.57±0.05

2007

0.88

0.80

0.61

0.83

0.69

0.53

0.74

0.55

0.83

0.38

1.00

1.00

0.94

0.67

0.38

0.52

0.60

0.24

0.67±0.05

Literature Reviewed:

Atlin, G.N., Lafitte, H.R., Tao, D., Laza, M., Amante, M., Courtois, B., 2006. Developing

rice cultivars for high-fertility upland systems in the Asian tropics. Field Crop

Res. 97, 43–52.

Amurrio, J.M., deRon, A.M., Zeven, A.C., 1995. Numerical taxonomy of Iberian pea

landraces based on quantitative and qualitative characters. Euphytica. 82, 195-205.

Louette, D., 2000. Traditional management of seed and genetic diversity: what is a landrace? Pp.

109-142 in Genes in the Field: On-farm Conservation of Crop Diversity (S.B. Brush,

ed.). IPGRI, IDRC, and Lewis Publishers, USA.

Harlan, J.R., 1975. Crops and man. American Society of Agronomy, Crop Science Society of

America,Madison, Wisconsin, USA.

Virk PS, Ford-Lloyd, BV., Jackson, MT., Pooni HS, Clemeno TP and Newbury J (1996)

Predicting quantitative variation within rice germplasm using molecular markers.

Smith, S.E., L. Guarino, A. Al. Doss and D.M. Conta. 1995. Morphological and agronomic

affinities among Middle Eastern alfalfas accessions from Oman and Yemen. Crop

Science, 35: 1118-1194.

Ghafoor, A., Z. Ahmad, N.I. Hashmi and M. Bashir. 2003. Genetic diversity based on

agronomic traits and SDS-PAGE markers in relation to geographic pattern of

blackgram [Vigna mungo (L.) Hepper]. Journal of Genetics & Breeding, 57: 5-14.

Zhu, L., R.G. Li and X.M. Wu. 1998. RAPD analysis in part of Chinese B. campestris. Biol.

Divers., 6: 99-104.

Virk, P.S., Newbury,H.J., Jackson, M.T., Ford-Lloyd, B.V., 1995. The identification of

duplicate accessions within a rice germplasm collection using RAPD analysis.

Theor.Appl.Genet. 90, 1049- 1055.

Virk, P.S., B.V. Ford-Lloyd, M.T. Jackson, H.S. Pooni, T.P. Clemeno and H.J. Newbury. 1996.

Predicting quantitative variation within rice germplasm using molecular markers.

Heredity 76:296-304.

Harlan, J.R. 1975. Crops and man. American Society of Agronomy, Crop Science Society of

America, Madison, Wisconsin, USA.

Allard, RW. 1999. Principles of plant breeding. 2nd edition. John Willey & Sons, Inc. New

York, USA.

Louette, D. 2000. Traditional management of seed and genetic diversity: what is a landrace? Pp.

109-142 in Genes in the Field: On-farm Conservation of Crop Diversity (S.B. Brush,

ed.). IPGRI, IDRC, and Lewis Publishers, USA.

Zhu, J. 1996. DNA fingerprinting in Oryza sativa L. A PhD Thesis submitted to University of

East Anglia, John Innes Centre, UK.

Trait

Character

Punjab

Sindh

NWFP

Trait

Character

Punjab

Sindh

NWFP

Flag leaf angle

Erect

39.87

30

9.09

Awn color

No awn

35.29

20

0

Intermediate

27.45

70

90.9

White

60.78

80

100

Horizontal

20.26

0

0

Light brown

1.31

0

0

Descending

12.42

0

0

Brown

0.65

0

0

Flag leaf shape

Erect

39.87

40

9.09

Dark brown

0.65

0

0

Semi-erect

40.52

60

90.9

Red

1.31

0

0

Droopy

19.61

0

0

Seed coat color

White

5.88

0

0

Leaf appearance

Narrow

24.84

0

90.9

Light brown

33.33

10

9.09091

Intermediate

75.16

100

9.09

Speckled brown

9.15

40

0

Broad

0.00

0

0

Brown

32.03

50

90.9091

Lodging

Heavy lodging

39.87

90

9.09

Red

3.27

0

0

Slight lodging

49.02

0

90.9

Variable purple

8.50

0

0

Absent

11.11

10

0

Purple

0.00

0

0

Panicle type

Compact

49.02

20

27.3

Reddish brown

7.84

0

0

Intermediate

5.88

10

63.6

Panicle exertion

Well exerted

52.94

60

27.2727

Open

45.10

70

9.09

Moderately exerted

14.38

40

63.6364

Awning

Awned

56.86

50

9.09

Just exerted

22.22

0

0

Awnletted

9.15

30

54.5

Partly exerted

10.46

0

9.09091

Awnless

33.99

20

36.4

Enclosed

0.00

0

0

9



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