Identification of Drought Tolerance on the Main Agronomic Traits for Rice (Oryza sativa L. ssp. japonica) Germplasm in China

Abstract

Drought is a major abiotic factor restricting rice yield; therefore, to cope with this stress, 2030 japonica rice accessions from China and other countries were evaluated in Beijing in 2017 and 2018. This was the first time six agronomic traits in the large-scale germplasm of rice under lowland and upland conditions with an augmented randomized complete block design (ARCBD) were analysed. The genotypes revealing drought resistant grade (DRG) scores of 1, 1–3, 3 and 3–5 were considered drought-tolerant and comprised 10% of the assessed germplasm. These findings were consistent with the agglomerative hierarchical cluster (AHC) analysis that classified germplasm in nine clusters. The generated clusters were further grouped in A, B, C and D classes based on the stress response. Approximately half of the genotypes with an upland ecotype were distributed in drought-resistant class A (cluster VII and VI) and moderately resistant class B (VIII and IX). The majority of the genotypes from China, Korea and Japan fall in drought-susceptible classes C and D. Genotypes of DRG 1, 1–3 and 3 belonged to the clusters VII and VI. Finally, we screened out 42 elite genotypes including seven improved upland rice lines (D78, LB37-13, NSU77, Handao 385, Handao 306, SF83 and HF6-65-119), three upland released varieties (Liaogeng 27, Hanfeng 8 and IRAT109) and three traditional lowland cultivars (Hongmaodao, Weiguo 7 and Xiaohongbandao). These genotypes might be used as priority parents in drought-tolerant rice breeding programmes and some of them could be recommended directly to farmers in water-deficient rice areas of China.

Utilising genetic variability and diversity analysis as a tool to identify drought tolerant pre-breeding genetic materials in rice (Oryza sativa L.)

“…The maximum inter-cluster distance of 6335.18 was observed between cluster X and cluster X1 indicating hybridization between genotypes of these clusters may be expected to result in better recombinant with the accumulation of favourable genes in segregating generations. Similar findings from Ahmad et al, 2021 and Singh et al, 2021 [3,16] . also suggested that hybridization between the genotypes from clusters with maximum inter-cluster distance helps in achieving heterotic recombinants.…”

“…High estimates of PCV and GCV for traits viz., leaf area (46.66 and 45.55), total leaves per plant (39.88 and 37.45) and number of panicles (38.39 and 35.40) respectively. Similar findings were reported by Singh et al, 2021 and Ahmad et al, 2021[16,3] . Moderate PCV and GCV were recorded for plant height (10.05 and 9.88), No.…”

“…This indicated that the materials used for the study is quite diverse for yield and drought traits. [3,18,20] also observed a similar clustering pattern for 54, 43 and 24 upland rice genotypes, respectively. Detailed insight into clustering pattern pointed out that 18 out of 50 genotypes belong to the same cluster i.e., cluster III.…”

Effect of Qiangdi 863 Nanosynergids Treated Water, Nitrogen, Phosphorous and Potassium Fertilizers on Rice Growth Physiology and Grain Quality

“…In the last 30 years, the worldwide area specified for rice cultivation is 155.5 million hectares with about 0.39% annual growth. Most probably, this number might increase from 2.7 billion to 4.6 billion people by 2050 ( Ahmad M. S. et al, 2021 ). Hence to the meet increased demand for rice, annual rice production of the whole world might have to increase by 70% from 520 million tons to 880 million tons by the year 2025.…”