I= GENETIC STABILITY OF MORPHO-PHYSIOLOGICAL, YIELD AND QUALITY DETERMINANTS OF VARIETAL GENUINENESS IN WHEAT (TRITICUM AESTIVUM L.)
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Title of Thesis
GENETIC STABILITY OF MORPHO-PHYSIOLOGICAL, YIELD AND QUALITY DETERMINANTS OF VARIETAL GENUINENESS IN WHEAT (TRITICUM AESTIVUM L.)

Author(s)
Muhammad Ashraf Tajammal
Institute/University/Department Details
Department of Biological Sciences/ Quaid-i-Azam University, Islamabad
Session
1997
Subject
Biological Sciences
Number of Pages
231
Keywords (Extracted from title, table of contents and abstract of thesis)
genetic stability, wheat, triticum aestivum l, pak 81, inqalab 91, pasban 90, rohtas 90, pirsabak 85, pirsabak 91, khyber 87, soghat 90, sindh 81, sarsabz, hmw glutenin subunits

Abstract
Testing genotypes in different environments is important for evaluating stability of performance and range of adaptation. The objective of this study was to determine genotype-environment interaction, stability and adaptability of various characters and effect of different environments on association of characters with grain yield and grain protein percentage in spring wheat (Triticum aestivum L.). Ten genotypes viz. Pak 81, Inqalab 91, Pasban 90, Rohtas 90, Pirsabak 85, Pirsabak 91, Khyber 87, Soghat 90, Sindh 81 and Sarsabz were evaluated at nine different locations for two years in 1993-94 and 1994-95. Data were recorded on various plant characters like plant height, peduncle length, flag leaf area, productive tillers per meter, spike length, number of spikelets per spike, rachis segment length, number of grains per spike, 1000-grain weight, grain protein percentage, number of maturity days and grain yield.

Electrophoretic analysis revealed good baking quality of genotypes showing 9.2 average quality score. Genotypes were distinct on the basis of HMW glutenin subunits composition used in combination with morphological characters.

Genotype-location, genotype-year and genotype-location-year interactions were highly significant for all characters. The relative magnitudes of interaction variance components viz., a2gl, a2gy and a2gly indicated that relative performance of genotypes for plant height, peduncle length, flag leaf area, productive tillers per meter, rachis segment length, 1OOO-grain weight, grain protein percentage and grain yield was more inconsistent across locations than years. The opposite was true for spike length, spikelets per spike, grains per spike and maturity days.

Stability parameters i.e. within genotype mean square {Si2}, genotype coefficient of variation {CVi%}, ecovalence {Wi}, genotype interaction variance (ai2), regression coefficient (bi), deviation from regression mean square (8i) and coefficient of determination {Ri2} revealed a range of stability for all characters.

Genotypes Pak 81, Inqalab 91 and Pirsabak 85 indicated good stability in almost all type of environments for grain protein percentage and maturity days, plant height, and flag leaf area, respectively. Soghat 90 and Sindh 81 reflected stability in high yielding environments for grains per spike, and 1000-grain weight, respectively whereas, in low yielding environments, Inqalab 91 exhibited stability for 1000-grain weight and grain yield, Pasban 90 for flag leaf area, grains per spike, maturity days and grain yield, Rohtas 90 for flag leaf area, productive tillers per meter, rachis segment length and grain protein percentage, Pirsabak 85 for peduncle length, Soghat 90 for productive tillers per meter and spike length, Sindh 81 for spike length, and Sarsabz for spikelets per spike.

Genotypes possessing small bi values were less efficient to take advantage of better agro-climatic conditions while, genotypes with regression coefficient near to 1.00 showed increase in their performance with an average amount as environmental conditions improve. Genotypes having large bi values implied serious decline in their performance as environmental conditions worsen.

Association of characters with grain yield and grain protein percentage was generally inconsistent across the locations. However, for the improvement of grain yield, concurrent selection based on plant height, flag leaf area, spike length, spikelets per spike, segment length, grains per spike and 1000-grain weight is possible.

Download Full Thesis
4534.18 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
295.86 KB
2 1 Introduction 1
62.52 KB
3 2 Review Of Literature 5
217.17 KB
  2.1 Electrophoresis 5
  2.2 Genotype-Environment Interaction And Stability 7
  2.3 Correlation 16
4 3 Materials And Methods 22
163.98 KB
  3.1 Electrophoretic Studies 22
  3.2 Experimental Studies 23
  3.3 Statistics Applied 29
5 4 Experimental Results 34
2520.66 KB
  4.1 Quality And Identity Of Genotypes 34
  4.2 Field Experimental Studies 34
6 5 Discussion 118
1534.76 KB
  5.1 Quality And Identity Of Genotypes 119
  5.2 Field Experimental Studies 121