الفهرس 
Genetic analysis of yield and yield contributing characters and juice quality traitsOnly 14 pages are availabe for public view
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Abstract
The present investigation is carried out in Genetic Engineering and Biotechnology Research Institute (GEBRI), University of Sadat city Egypt in cooperation with Genetics Department, Faculty of Agriculture, Assiut University and Genetic Engineering and Tissue Culture Research Unit, Assiut University, Assiut, Egypt during the period 2008 to 2013.The investigation aimed to study the following objectives:
I- Study and analysis genetics of some agronomical and juice quality traits in sugarcane to detect their expected response to selection.
II- determination of genetic variability and relationships among 12 sugarcane genotypes based on TRAP markers of seven candidate genes involved in sucrose metabolism namely; sucrose synthase (SuSy), sucrose-phosphate synthase (SuPS), starch synthase (StSy), soluble acid invertase (SAI), pyruvate orthophosphate dikinase (PPDK), dirigent protein related to high sugar content (Dir-H) and dirigent protein related to low sugar content (Dir-L).
III- Evaluation the performance of 12 sugarcane genotypes under drought stress and determination of genetic variability among them using TRAP markers of Aquaporin (Aqua) and Dehydration Binding Factor (DBF) candidate genes involved in drought tolerance.
Twelve genotypes of sugarcane (Saccharum officinarum L.) namely; EH 16-9, EI 8-129, EI 264-2, EI 266-2, EI 24-2 OR 3, G84 – 47, G99-103, G2000 -79, GT54-9, NCO310, N26 and PH8013 are used in the present investigation. The results obtained could be summarized as follow:
I- Genetic analysis and expected response to selection for some agronomical and juice quality traits in sugarcane.
1- Highly significant differences are found for years, genotypes and their interaction in all studied traits, except year and interaction of stalk diameter.
2- The phenotypic and genotypic coefficients of variation (PCV and GCV) are moderate to high for stalk height, stalk weight, number of stalks/m2, cane yield, sugar yield, and reducers %.
3- Low values of GCV and PCV are found in stalk diameter, recoverable sucrose %, Brix (%), Pol%, Purity (%) and Fibers %, which reflect lower variability in these traits.
4- Maximum genetic gain along with high heritability is observed for stalk height, cane yield, stalk weight, and sugar yield.
5- Reducers% showed high genetic gain and moderate heritability while, number of stalks/m2 showed moderate genetic gain and heritability estimates.
6- High value of heritability associated with low to moderate genetic gain are observed for Purity% and stalk diameter.
7- Low genetic gain with moderate value of heritability are observed for recoverable sucrose %, Brix%, Pol%, and Fibre%.
8- The positive correlation between cane or sugar yield and each of number of stalks/m2, stalk weight, stalk diameter and stalk height indicated the improvement in any of these traits might result in positive response of the cane yield.
9- The undesirable negative correlations between Brix% and stalk weight as well as between Pol% and each of stalk weight and stalk height suggested that number of stalks/m2 might be used as selection criteria to improve sugar yield.
10- The results suggested that genotypes G2000-79 and EI 264-2 could be used in selection programs to improve sugar yield.