The objective of the recent study was to detect variability in Egyptian multi-cut barseem gene pool via studying four
different commercial populations regarding seed yield and seed yield components. These were; Khadarwi, Meskawi,
Serow and Helaly. Means of total seed weight.plant-1were approximately similar for Khadarawi (26.131g) and Meskawi
(26.122) population. This was affected by similar figures for seed yield components. Serow population scored the least
seed weight.plant-1 (21.981g) affected largely by the least number of seed.head-1 (37.79 seed.head-1). Meanwhile, Helaly
population had the second least total seed weight.plant-1 (23.49g) affected also by low figure of number of seed.head-1.
Major proportion of total variance (σ2p)was contributed by the genotypic component (σ2g) in total seed weight. plant-1 and
number of heads.plant-1in all studied barseem populations. Whereas, the genotypic variance represented a very limited
portion of phenotypic variance for other studied seed yield components in all studied populations. Heritability estimates in
khadarawi and Meskawi populations postulated a strong genetic control on total seed weight .plant-1 and number of heads.
plant-1 (0.98 and 0.97%). While, weak estimates were recorded for number of seeds.head-1, seed weight.head-1and 1000
seed weight (0.23, 0.13 and 0.04%, respectively). Estimates of expected gain from selection the top 10% of half-sib
families of khadarawi population might result in 59.85% increase in total seed weight, which amount to15.64 g.plant-
1.Concerning Helaly population selecting the top 10% of half-sib families might result in total seed weight.plant-1 and
number heads.plant-1 increase of 72.43 and 67.09% which might amount to 17.01g.plant-1 and 105.8heads.plant-1.