Development and evaluation of Fusarium wilt-resistant and high-yielding chickpea advanced breeding line, KCD 11.

Fusarium wilt (FW) is the most severe soil-borne disease of chickpea that causes yield losses up to 100%. To improve FW resistance in JG 11, a high-yielding variety that became susceptible to FW, we used WR 315 as the donor parent and followed the pedigree breeding method. Based on disease resistance and yield performance, four lines were evaluated in station trials during 2017-2018 and 2018-2019 at Kalaburagi, India. Further, two lines, namely, Kalaburagi chickpea desi 5 (KCD 5) and KCD 11, which possesses the resistance allele for a specific single-nucleotide polymorphism marker linked with FW resistance, were evaluated across six different locations (Bidar, Kalaburagi, Raichur, Siruguppa, Bhimarayanagudi and Hagari) over a span of 3 years (2020-2021, 2021-2022 and 2022-2023). KCD 11 exhibited notable performance, showcasing yield advantages of 8.67%, 11.26% and 23.88% over JG 11, and the regional checks Super Annigeri 1 (SA 1) and Annigeri 1, respectively, with enhanced FW resistance in wilt sick plot. Further, KCD 11 outperformed JG 11, SA 1 and Annigeri 1 in multi-location trials conducted across three seasons in the North Eastern Transition Zone, North Eastern Dry Zone, and North Dry Zones of Karnataka. KCD 11 was also tested in trials conducted by All India Coordinated Research Project on chickpea and was also nominated for state varietal trials for its release as a FW-resistant and high-yielding variety. The selected line is anticipated to cater the needs of chickpea growers with the dual advantage of yield increment and disease resistance.

Consequence of cyclic pollen selection for heat tolerance on the performance of different generations in maize (Zea mays L.).

The reproductive stage in many crops, including maize, is very sensitive to heat stress and the genetic overlap between gametophytic and sporophytic phase gives an opportunity to select superior stress tolerant genotype at gametophytic stage. An attempt was made to evaluate the response of cyclic pollen selection in the F1 and F2 generations on the performance of F3 generation progenies for seed yield and yield contributing traits under natural heat stress conditions. In this direction three groups of F3 progenies, namely (i) pollen selection in F1 and F2 generations (GG), (ii) pollen selection only in F2 generation (CG), (iii) no pollen selection in F1 and F2 generations (CC) were screened for heat stress at Agricultural Research Station (ARS), Bheemarayanagudi. The GG progenies recorded significantly higher chlorophyll content, more number of pollen grains per anther and less pollen sterility compared to CG and CC group of progenies under heat stress. Further, the F4 progenies obtained through cyclic pollen selection (in F1, F2 and F3) were also tested for heat stress tolerance at seedling stage. The significant improvement for heat stress tolerance was recorded in F4 progenies derived through cyclic pollen selection as compared to control (no pollen selection for heat tolerance in any generation) F4 progenies. The results indicated that cyclic pollen selection in F1, F2 and F3 generations improved the heat stress tolerance of the progenies in the succeeding generations. To provide genetic evidence for the effect of pollen selection for heat tolerance, the control F2 (C) and selected F2 (G) populations were compared for the segregation of SSR markers. The selected F2 (G) population showed significant deviation from normal Mendelian ratio of 1:2:1 and showed skewness towards the alleles selected from male parent. The results provide strong evidence for an increase in the frequency of parental alleles in the progenies that impart heat stress tolerance.