Pedigree selection in sesame under artificial infection of Fusarium oxysporum f. sp. sesami

Abstract

Fusarium is one of the most dangerous fungal diseases that cause great loss of the sesame yield worldwide. The present work aimed to improve tolerance and/or resistance to Fusarium through two cycles of pedigree selection on sesame population for eight selection criteria started in the F 3 -generation. Genotypic coefficient of variability in the F 3 varied from 4.34% for days to 50% flowering to 38.15% for seed yield (SY/P). Days to 50% flowering showed negative correlations with all traits except height to first capsule (HFC). Height to first capsule was negatively correlated with length of fruiting zone (LFZ), 1000-SW, oil% and infection%, and positively correlated with capsules/plant (NC/P) and SY/P. Single trait selection was an efficient method to improve selection criterion, but it caused adverse effects on some correlated traits. Selection for days to 50% flowering improved earliness, but it was better in improving yield if the selection was restricted by SY/P. Selection for oil% restricted by yield was better in improving yield than selection for oil% per se. Therefore, the inclusion of a trait as independent culling level improved the efficiency of selection. The best genetic gain in SY/P in percentage from the mid-parent was obtained from selection for days to 50% flowering restricted by SY/P (35.56 ** ), LFZ restricted by HFC (19.53 ** ), days to 50% flowering (19.32 ** ), oil% restricted by SY/P (19.02 ** ), SY/P (17.38 ** ), 1000 SW (14.09 ** ) and LFZ (14.032 ** ). Therefore, selection index incorporating favorable trait is recommended.

Improving Sesame (Sesamum indicum L.) Seed Yield through Selection under Infection of Fusarium oxysporum f. sp. sesami

“…The correlated gains were favorable for LFZ, NCP −1 , SYP −1 , and infection %. These results are in accordance with those noted by [21,33]. However, selection for PH significantly delayed earliness.…”

“…[19] noted gains in HFC of −56.71% and −56.17% of the better parent for two populations, after two cycles of selection. The positive significant correlations among PH, LFZ, and SYP −1 in the base populations played an important role in pedigree selection [21,23,26,33]. The direct genetic response to selection for LFZ was significant (p ≤ 0.05-p ≤ 0.01).…”

“…Hence, SYP −1 as a restricted trait, when selected for earliness, mitigated the effects of the negative correlations of earliness with the other traits, and significantly increased the observed genetic gains in PH, LFZ, and SYP −1 . As it was found that selection for FLOW(R) was better than selection for earliness per se [33].…”

Pedigree Selection in Improving Seed Yield and Tolerance of Sesame to Macrophomina phaseolina (Tassi) Goid

“…The experiment in the F 3 , F 4 and F 5 generation was laid out in randomized complete block design (RCBD) with three replications. The details of growing seasons and planting dates can be found in Mahdy et al (2021).…”

“…The preparation and isolation of the Macrophomina phaseolina (Tassi) Goid fungus was done according to Booth (1971), and Mahmoud (2016) (See Mahdy et al, 2021).…”