Low phosphorus response and allelic footprints in paddy (Oryza sativa L.) landraces from the Chhotanagpur plateau, India: implications for crop genetics and nutrient management
摘要
The study identified significant diversity in paddy traits, including number of effective tillers plant−1 (mean = 9; GCV = 36.23%), days to maturity (mean = 109 days; GCV = 25.20%), time to heading (mean = 79 days; GCV = 24.58%), and stem length (mean = 89.01 cm; CV = 19.38%). Correlation analysis showed positive associations between grain yield plant−1, panicle length (each 0.45***), number of effective tillers plant−1 (0.44***), and stem length (0.37***). Conversely, time to heading had a negative association with grain yield plant−1 (−0.38***). Low soil P significantly reduced paddy grain yield plant−1 by 89.98% but positively impacted time to heading (28.23%) and days to maturity (12.45%). The population was categorized into tolerant, intermediate, and susceptible sub-populations based on grain yield plant−1 reduction. Fifteen Pup1 gene-associated primers were amplified, with the highest PIC values of K20-2 (0.500) and K1 (0.498). The tolerant sub-population showed the highest effective number of alleles (1.777), while the intermediate sub-population had the highest Shannon's Information index (0.618). Overall, the population's effective number of alleles was 1.756, and the maximum Nei genetic distance was between the susceptible and tolerant groups (0.034). Sub-population III was identified with 31 low soil P-tolerant genotypes, with Karhani landrace (PYR = 3.49) showing the best tolerance compared to checks like Sahbhagi (PYR = 5.55) and Kaisalath (PYR = 4.59). Only 4 Pup1 markers were amplified in Karhani, compared to 12 in Sahbhagi and 14 in Kaisalath, highlighting little contribution of Pup1 gene-associated allele in conferring low soil P tolerance in the genotype. Detailed study of the genotype may further reveal novel genetic factor underlying the phenomena.