Direct-seeded rice as a promising approach for sustainable rice cultivation: multi-trait evaluation and selection of adapted genotypes

Abstract

Rice acts as a staple cereal food for most of the Asian population. Interruption of climate change, water requirements, and labour shortages affect the cultivation of rice. DSR is the alternate strategy for rice cultivation in South Asia. In this study, thirty genotypes were evaluated under three crop establishment methods, viz., dry direct-seeded rice, wet direct-seeded rice and transplanted rice. Twenty-two phenological, physiological, yield-associated traits and grain quality traits were recorded. This study aims to identify the best crop establishment method along with suitable genotypes for that environment. Phenotypic correlation analysis revealed positive association with shoot fresh weight, shoot dry weight, number of spikelets per panicle and panicle fertility percentage across all three establishment methods, while number of productive tillers per plant and thousand grain weight also contributed significantly under wet and dry direct-seeded conditions, respectively. Cluster analysis classified the genotypes into five distinct clusters within each crop establishment method, indicating substantial genetic divergence and variability among the evaluated genotypes. multi-trait genotype-ideotype distance index identified MTU 2716, I.W. Ponni, PKM 4, KR 21003, CO 51, ADT 58, KKL(R) 2 and TKM 9 for DDSR. In WDSR, MTU 2716, I.W. Ponni, ADT 48, IR 50, CO 51, ADT 54, KKL(R) 2 and KR 21002; and for TPR, BPT 5204, IR 20, I.M. Samba Mashuri, MTU 2716, KR 21003, IR 50, KKL(R) 2 and CO 51. Box-and-whisker plot clearly explains that E2P (WDSR) is the best environment among the three establishment methods. The differential performance of genotypes across crop establishment methods indicates the importance of environment-specific evaluation for identifying adapted rice genotypes. The superior performance of WDSR (E2P) suggests its potential as a suitable crop establishment method for sustainable rice cultivation under the tested conditions. Multi-trait selection effectively identified genotypes combining desirable agronomic and yield-associated traits across establishment methods. These findings highlight the usefulness of integrating crop establishment methods with multi-trait genotype selection for developing and identifying rice genotypes suited to resource-efficient production systems.