I= GENETIC DIVERSITY AND GENE ACTION IN MUNGBEAN
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Title of Thesis
GENETIC DIVERSITY AND GENE ACTION IN MUNGBEAN

Author(s)
Muhammad Zubair
Institute/University/Department Details
University of Arid Agriculture/Plant Breeding and Genetic
Session
2004
Subject
Plant Breeding and Genetic
Number of Pages
196
Keywords (Extracted from title, table of contents and abstract of thesis)
genetic diversity, morphological characters, mungbean germplasm, branches per plant, pods per plant, seeds per pod, grain yield per plant, biological yield per plant, harvest index

Abstract
Mungbean germplasm comprising 262 accessions was evaluated for agro-morphological traits at National Agricultural Research Centre (NARC), Islamabad. Eighty selected accessions were included in biochemical (SDS-P AGE) analysis. In addition, genetic studies were conducted on eight mungbean genotypes in an 8x8 diallel cross.

High variance was observed for days to maturity, branches per plant, pods per plant, seeds per pod, grain yield per plant, biological yield per plant and harvest index. Grain yield per plant showed significantly positive correlation with branches per plant, pods per plant, biological yield per plant and harvest index. Negative association of biological yield with harvest index showed physiological inefficiency for appropriate partitioning of total dry matter towards economic yield, consequently the accessions with low grain yield attained low harvest index. The germplasm accessions were grouped into six clusters on average linkage basis. First three principal components (PCs) with eigenvalues>1 contributed 71.47% of the variability amongst the accessions. The populations with greater PC1 values were high yielding, late maturing and were characterized by high number of branches with more pods. The second component was strongly associated with earliness, more number of seeds and high harvest index. Green seed coat colour and shiny seed lustre proved their importance in selection for improving most of the yield contributing traits.

The SDS-PAGE conducted in various combinations revealed that 15% acrylamide gel concentration and 8 μl of sample quantity gave the best resolution. Out of 18 SDS-PAGE markers, 9 were polymorphic. The Protein peptide, 10a alone, revealed importance for detection of six important yield contributing characters, followed by bands, 2a and 7, each of which indicated its significance for four yield components. The association of biochemical variation with QTLs can be used for germplasm screening and further exploitation for mungbean improvement.

For gene action studies, data were analyzed following techniques viz. analysis of variance, combining ability analysis, genetic component analysis and Wr, Vr graphic analysis. Estimates of variances due to general combining ability (GCA) and specific combining ability (SCA) suggested predominance of additive gene action for plant height, days to maturity, pod length and 100 seed weight. High SCA variance for pods per plant, seeds per pod and grain yield per plant revealed the importance of non-additive gene action for these characters. The genotype, NM 51, was the best general combiner for pods per plant and grain yield per plant. The cross combination, NM 121-25 x VC 4152, was at the top for high grain yield on the basis of SCA. For the improvement of grain yield in mungbean, crosses involving the parents, NM-121-25, NM-51, VC-3902 and VC-4152, must be given special consideration.

The estimates of components of genetic variation (Hayman's approach) showed that additive genetic effects appeared to be important for plant height, days to maturity, pod length and 100 seed weight. The non-additive effects were more pronounced in the genetic control of pods per plant, seeds per pod and grain yield per plant. Directional dominance was observed for plant height, pods per plant, seeds per pod and grain yield per plant. The parents contained equal number of dominant genes for all the characters except 100 seed weight for which the genes were distributed asymmetrically among the parental lines. The graphic analysis revealed partial dominance for all the characters studied. Plant height, days to maturity, pod length and 100 seed weight being controlled by additive genetic effects with partial dominance will certainly provide the basis for selection in early segregating generations for improvement in these parameters.

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S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
23.51 KB
2 1 Introduction 3
59.09 KB
3 2 Review Of Literature 8
203.33 KB
  2.1 Genetic Diversity Based On Morphological Characters 8
  2.2 Biochemical ( Sds -Page) Basis Of Genetic Diversity 16
  2.3 Inheritance Of Quantitative Characters 21
  2.3.1 Combining Ability Analysis ( Griffing's Approach) 22
  2.3.2 Genetic Analysis ( Hayman's Approach) 25
4 3 Materials And Methods 28
157.02 KB
  3.1 Genetic Diversity Based On Morphological Characters 28
  3.1.1 Germplasm Collection 28
  3.1.2 Experimental Material 29
  3.1.3 Statistical Analysis 32
  3.2 Biochemical ( Sds -P Age) Basis Of Genetic Diversity 34
  3.2.1 Plant Material 34
  3.2.2 Protein Extraction 35
  3.2.3 Electrophoresis 35
  3.2.4 Staining an4 Destaining 36
  3.2.5 Data Analysis 36
  3.3 Inheritance Of Quantitative Characters 37
  3.3.1 Experimental Material and Planting 37
  3.3.2 Data Collection 37
  3.3.3 Statistical Analysis 38
  3.3.3.1 Griffing’s method 38
  3.3.3.2 Hayman's method 39
  3.3.3.2.1 Testing the validity of the hypothesis 39
  3.3.3.2.2 Genetic parameters 40
  3.3.3.2.3 Graphic analysis 41
5 4 Results And Discussion 43
873.19 KB
  4.1 Genetic Diversity Based On Morphological Characters 43
  4.1.1 Quantitative Characters 43
  4.1.1.1 Correlation analysis 53
  4.1.1.2 Cluster analysis 55
  4.1.1.3 Principal component analysis 60
  4.1.2 Qualitative Characters 65
  4.1.2.1 Significance of qualitative characters in determining Quantitative traits loci ( QTLs ) 67
  4.1.3 Viral diseases 69
  4.1.3.1 Mungbean yellow mosaic virus (MYMV) 69
  4.1.3.2 Urdbean leaf crinkle virus (ULCV) 71
  4.1.4 Geographic Distribution 71
  4.1.4.1 Provinces 73
  4.1.4.2 Altitude 76
  4.1.4.3 Crop ecological zones 80
  4.2 Biochemical (SDS-P AGE) Basis Of Genetic Diversity 87
  4.2.1 Significance of Protein Subunits on QTLs 90
  4.2.2 Cluster and Principal Component Analyses Based on SDS-P AGE 97
  4.2.3 Cluster and Principal Component Analyses Based on Agronomic Traits 101
  4.3 Genetic Studies And Mode Of Inheritance 110
  4.3.1 Estimation of Combining Ability ( Griffing's approach) 110
  4.3.1.1 General combining ability effects 113
  4.3.1.2 Specific combining ability effects 116
  4.3.1.3 Reciprocal effects 119
  4.3.2 Genetic Analysis ( Hayman's approach) 124
  4.3.2.1 Validity of assumptions 133
  4.3.2.2 Estimation of genetic parameters 137
  4.3.2.3 Wr , Vr graphic analysis 142
6 5 Summary 154
55.92 KB
7 6 Literature Cited 159
207.92 KB
8 7 Appendices 184
78.69 KB