Rice Research Department, Field Crops Research Institute, Agricultural Research Center, Giza 12619, Egypt.
Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
Genes (Basel). 2022 May 19;13(5):906. doi: 10.3390/genes13050906.
This study aimed to identify new rice lines and hybrids that are tolerant to water deficit and produce high yields under water stress conditions. A line × tester mating design was used to study the lines and testers' general combining ability (GCA) effects. The specific combining ability (SCA) of the hybrid rice combinations was measured under three different irrigation regimes; 6, 9, and 12 days. The study was carried out at the experimental farm of Sakha Agricultural Research Station, Sakha, Kafr El-Sheikh, Egypt, during the 2018 and 2019 rice growing seasons. Due to the genotypes and their partitions to the parents and the crosses, the mean squares were highly significant for all studied traits under the three irrigation regimes. The additive gene effects play an important role in expressing most of the studied traits. Therefore, the selection procedures based on the accumulation of the additive effect would be successful at improving these traits and the grain yield. The cytoplasmic male sterile (CMS) line G46A (L1) was the best combiner for most yield component traits in the three irrigation regimes. The newly devolved restorer lines T11, T1, T2, T5, T4, and T3, as well as the new hybrids L2 × T10, L2 × T6, L1 × T7, L1 × T5, L1 × T3, L2 × T7, L2 × T9, L2 × T8, L2 × T4, L1 × T4, L2 × T2, L1 × T8, L1 × T9, and L2 × NRL 10, showed good, desirable values of the studied traits such as earliness of flowering, short plant height, number of panicles/plant, panicle length, number of spikelets/panicle, number of filled grains/panicle, panicle weight, 1000-grain weight, hulling percentage, milling percentage, head rice percentage, and grain yield under the irrigation regimes of 6, 9, and 12 days. The hybrids L2 × T10, L2 × T6, L1 × T7, and L1 × T5, showed significant positive SCA effects for grain yield, under all three irrigation regimes.
本研究旨在鉴定新的水稻品系和杂种，使其在水分亏缺条件下具有耐受性，并在水分胁迫条件下获得高产。采用系×测交设计研究了系和测交亲本的一般配合力（GCA）效应。在三个不同的灌溉制度下，即 6、9 和 12 天，测量了杂交水稻组合的特殊配合力（SCA）。该研究在埃及 Kafr El-Sheikh 的 Sakha 农业研究站的实验农场进行，在 2018 年和 2019 年的水稻生长季节进行。由于基因型及其在父母和杂交中的分配，在三个灌溉制度下，所有研究性状的均方都高度显著。加性基因效应在表达大多数研究性状方面起着重要作用。因此，基于累加加性效应的选择程序将成功地用于改良这些性状和籽粒产量。细胞质雄性不育（CMS）系 G46A（L1）是三个灌溉制度下大多数产量构成性状的最佳组合。新选育的恢复系 T11、T1、T2、T5、T4 和 T3，以及新杂交种 L2×T10、L2×T6、L1×T7、L1×T5、L1×T3、L2×T7、L2×T9、L2×T8、L2×T4、L1×T4、L2×T2、L1×T8、L1×T9 和 L2×NRL10，在 6、9 和 12 天的灌溉制度下，表现出良好的、理想的开花早、植株矮、穗数/株、穗长、小穗数/穗、实粒数/穗、穗重、千粒重、出糙率、整精米率、整精米率、精米率和籽粒产量等性状值。在三个灌溉制度下，杂交种 L2×T10、L2×T6、L1×T7 和 L1×T5 对籽粒产量表现出显著的正特殊配合力效应。
