Variation for Photoperiod and Temperature Sensitivity in the Global Mini Core Collection of Sorghum

Abstract

Information on photoperiod and temperature sensitivity of sorghum germplasm is important to identify appropriate sources for developing cultivars with a broad adaptation. The sorghum mini core collection consisting of 242 accessions along with three control cultivars were evaluated for days to 50% flowering (DFL) and plant height in two long-day rainy and two short-day post-rainy seasons, and for grain yield and 100-seed weight in the two post-rainy seasons. Differences in DFL and cumulative growing degree days (CGDD) in the rainy and post-rainy seasons were used to classify the accessions for photoperiod and temperature sensitivity. Results revealed 18 mini core landraces as photoperiod and temperature insensitive (PTINS), 205 as photoperiod sensitive and temperature insensitive (PSTINS), and 19 as photoperiod and temperature-sensitive (PTS) sources. The 19 PTS sources and 80 PSTINS sources took less DFL in the long-day rainy seasons than in the short-day post-rainy season indicating their adaptation to the rainy season and a possible different mechanism than that trigger flowering in the short-day sorghums. In all three groups, several accessions with desirable combinations of agronomic traits were identified for use in the breeding programs to develop climate-resilient cultivars and for genomic studies to identify genes responsible for the photoperiod and temperature responses.

Multi‐trait stability index for the identification of shoot fly (Atherigona soccata) resistant sorghum lines from a mini core collection

“…Based only on mean DH% over 3 years, lines IS 18551, IS 2205, IS 12697, IS 26222, IS 25732, IS 4631 were resistant (<44%–48% DH) while lines IS 31043, 296B, IS 23590, IS 33090 and IS 31651 were continually susceptible (69%–76% DH). IS 18551, IS 2205 are the stable resistant sources reported by earlier studies 23,24,37,49,50 . In the present study, IS12697 ( bicolor race from Australia), IS26222 ( Guinea‐caudatum from Togo), IS25732 ( durra from Mali), IS 4631 ( durra , India) were the new sources of resistance identified based on the lowest DH% over 3 years.…”

“…IS 18551, IS 2205 are the stable resistant sources reported by earlier studies. 23,24,37,49,50 In the present study, IS12697 (bicolor race from Australia), IS26222 (Guinea-caudatum from Togo), IS25732 (durra from Mali), IS 4631 (durra, India) were the new sources of resistance identified based on the lowest DH% over 3 years. IS 4631 was reported to be shoot fly resistant.…”

“…Mini core has been reported to be a source of genetic variability for various traits and genetic mapping 28,31–35,37,39,48 . However, no studies were conducted earlier to report the genetic variability for shoot fly component traits using the sorghum mini core set.…”

“…Mini core has been reported to be a source of genetic variability for various traits and genetic mapping. 28,[31][32][33][34][35]37,39,48 However, no studies were conducted earlier to report the genetic variability for shoot fly component traits using the sorghum mini core set. This study revealed significant genetic variability for each of the component traits (DH, SH, GS, Eggs, TDU, TDL, and EW) of shoot fly resistance.…”

“…The sorghum mini core set 27 contains the global diversity collected from 58 countries and represents all basic and intermediate sorghum races. The mini core set has been extensively used for characterization and genetic mapping of various traits: diseases, [28][29][30] forage biomass, 31 stalk sugar content, 32 iron and zinc, 33 protein, amylose and amylopectin, 34 productivity traits, 35 drought tolerance, 36 photoperiod and temperature sensitivity, 37 maturity and height 38,39 and germinability and seedling vigour. 40 However, this mini core set representing global genetic diversity has not been evaluated for shoot fly resistance, an important biotic stress on sorghum.…”