The Combining Ability for Grain Yield and Some Related Characteristics in Rice (Oryza sativa L.) Under Normal and Water Stress Conditions

Abstract

Drought is considered a major threat to rice production. This study aimed to determine the effects of drought stress on the estimates of heterosis and the combining ability of rice genotypes for the number of days to 50% heading, plant height, number of panicles per plant, panicle length, number of filled grains per panicle, and grain yield per plant. Field experiments were conducted at the Rice Research and Training Center, Kafr El Sheikh, Egypt, during the rice-growing season in 2018 and 2019. Eight rice genotypes (Giza178, Giza179, Sakha106, Sakha107, Sakha108, WAB1573, NERICA4, and IET1444) were crossed in a half-diallel cross in the rice-growing season in 2018, which yielded a wide range of variability in numerous agronomic traits and drought tolerance measurements. In 2019, these parents and their 28 F1 crosses were produced by employing a three-replication randomized complete block design under normal and water stress conditions. The results showed remarkable differences across the studied genotypes under normal and water stress conditions. Under both conditions, Sakha107 was the best general combiner for earliness and short stature. Giza179 and Sakha108 were the best general combiners for grain yield per plant and one or more of its characteristics. Furthermore, in both normal and water stress conditions, Giza179 exhibited the highest general combining ability effects for all attributes that were evaluated. Under normal and water stress conditions, the Giza179 × Sakha107 cross demonstrated substantial and desirable specific combining ability effects on all the examined traits, which suggested that it could be considered for use in rice hybrid breeding programs. Therefore, we recommend that these vital indirect selection criteria to be considered for improving rice grain yield under drought conditions.

Mode of gene action and heterosis for physiological, biochemical, and agronomic traits in some diverse rice genotypes under normal and drought conditions

“…It is the most significant constraint for rice production in rainfed habitats (Nelson et al, 2014;Pandey and Shukla, 2015;Abd El-Aty et al, 2022b). For instance, it causes considerable crop damage and a yield loss of more than 70% compared with normal conditions (Vaghefi et al, 2011;Abd El-Aty et al, 2022c;Abd El-Aty et al, 2022d).…”

“…In Egypt, the rising population and limited water supply meant that even with increased rice production, the rate of food production lagged behind the demand (Dianga et al, 2020;Abd El-Aty et al, 2022c). Thus, the rice sector's crop production and yield performance in Egypt has been impressive in the last three decades.…”

Exploration of quality variation and stability of hybrid rice under multi-environments

“…Therefore, breeders use the combining ability to assess the breeding value of parental materials in hybrid production (Sprague and Tatum 1942). By identifying the combining ability of parents in phenotype plasticity, the performance of hybrid combinations can be predicted, thereby improving the efficiency and stability of hybrid rice production (Abd El-Aty et al 2022).…”

Development of Two Novel Photoperiod and Thermo-Sensitive Genic Male Sterile Lines in Rice (Oryza sativa L.)

“…Hybrid rice technology is one of the effective ways to increase rice production leading to self-sufficiency and facing overpopulation in Egypt. With the release of conventional cultivars, rice yield levels have reached a plateau that can be broken with this technique (Abd El-Aty et al, 2022). Commercial hybrids often produced between 15 to 20% more than the most acceptable inbred varieties grown in comparable conditions, which were attributed to "hybrid vigor" or "heterosis" from mating the two parents (El Sayed et al, 2021;Melandri et al, 2021).…”

“…Commercial hybrids often produced between 15 to 20% more than the most acceptable inbred varieties grown in comparable conditions, which were attributed to "hybrid vigor" or "heterosis" from mating the two parents (El Sayed et al, 2021;Melandri et al, 2021). The superiority of hybrid varieties over inbred varieties in terms of grain output, vigor, panicle weight, number of spikelets per panicle, and number of productive tillers are examples of how hybrids can benefit from heterosis (Abd El-Aty et al, 2022).…”