Combining ability and heterosis for earliness, growth and biological yield of some flax genotypes at normal-irrigation and water-shortage [electronic resource]

Includes bibliographic reference

Six parents and their 15 F1 crosses were evaluated in 2019/2020 season under normal and drought-stress for earliness and its related traits of flax. A filed experiment was devoted for each normal and drought-stress), using RCBD with three replicates. Mean squares of general and specific combining abilities were highly significant for most traits, indicating the relative importance of both additive and non-additive influences of genes in the inheritance of these traits. δ2GCA δ2/SCA variances under normal-irrigation and drought-stress were greater than unity for days to maturity, plant height at harvest and stem diameter. P1 was found to be the best combiner for earliness under both conditions. While, P4 and P5 were good combiner for plant height at flowering and at harvest and biological yield under drought conditions. The best heterosis (mid and better parent) for the earliest hybrids was recorded by hybrid No. 11 under normal and hybrid No. 7 under drought. Hybrids No. 6 over mid-parents and No. 11 over better-parents under drought for days to maturity shown the best heterosis. While, hybrids No. 8 and 10 recorded the best heterosis for plant height at flowering under both situations. But, the best heterosis were recorded by hybrids No. 2 and 8 for plant height at harvest and hybrids No.7 and 13 for technical stem length shown under normal irrigation conditions. The hybrids No. 4 and 9 for biological yield per plant showed the best heterosis over mid and better parents under normal and drought conditions, respectively.
Keywords: Flax; Combining ability; Heterosis; earliness; growth; biological yield

Summary in Arabic