Fluctuating expression for sterility in cytoplasmic male sterile grain sorghum lines under high temperature conditions / Walaa Yaseen Saad Yaseen ; Supervised Ahmed Medhat Mohamed Alnaggar , Rabia Mohamed Abdelsalam , Mohamed Rizkalla Asran Hovny

Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Agronomy

The objectives of the present study were: (i) to estimate the effect of elevated temperature on the percentage of pollen sterility of cytoplasmic male sterile (CMS) A-lines and agronomic and yield traits of B-lines of grain sorghum (ii) to identify the A-lines that exhibit perfect or nearly perfect pollen sterility under elevated temperature and those exhibit fluctuation to fertility, (iii) to estimate heritability and genetic advance from selection for studied traits and (iv) to assess sorghum B-lines for yielding stability and adaptability. Twenty five CMS grain sorghum A-lines and their counterpart B-lines were evaluated under six environments differing in temperatures (Giza and Shandaweel in two years and two planting dates in Giza), using a randomized complete block design with three replications in each experiment. Results showed that across all A-lines, percentage of sterile pollen decreased as temperature increased; from 89.6% at maximum temperature of 35.2oC (at Giza 2012, 1st planting date) to 86.9% at maximum temperature of 40.8oC (at Shandaweel 2013)

Issued also as CD