Nagendra Naidu B, Swaminathan Manonmani, Ramamoorthy Pushpam, Dharmalingam Kumaresan, Muthurajan Raveendran, Duraisamy Selvi, Rakkimuthu Nivedha, Subramanian Abirami, Natarajan Rithesh, John Bonipas Antony
Department of Rice, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.
Department of Forage Crops, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.
PeerJ. 2025 May 8;13:e18975. doi: 10.7717/peerj.18975. eCollection 2025.
Thermo-sensitive genic male sterile (TGMS) lines in rice are crucial for hybrid breeding, enhancing genetic diversity by eliminating the need for manual emasculation and restorer genes. These lines induce sterility at high temperatures and restore fertility at low temperatures, in contrast to cytoplasmic male sterility (CMS) systems that require specific restorative genes. This temperature-sensitive mechanism allows for greater flexibility in pairing parent lines, increasing genetic diversity and enabling recombination of beneficial traits in hybrids. A randomized block design (RBD) with three replications was employed for the evaluation of these TGMS rice lines. This study investigates the molecular diversity and genetic variability among TGMS rice lines. Traits such as single plant yield, grains per panicle, glume angle, and pollen fertility showed significant phenotypic and genotypic variation, indicated by high coefficients of variation (PCV and GCV), heritability estimates, and genetic advance as a percentage of mean (GAM). These results highlight substantial genetic variation and selection potential. Euclidean distance matrix analysis of morphological data revealed notable genetic differences. TNAU 137S 1 and TNAU 137S 2 were the most genetically similar, while TNAU 112S and TNAU 114S showed the greatest divergence. Principal component analysis (PCA) revealed distinct genetic profiles among lines such as TNAU 136S, TNAU 113S, TNAU 142S, and TNAU 126S, important for hybrid development. Molecular diversity analysis using simple sequence repeat (SSR) markers identified 90 alleles and eight genetic clusters. Bayesian analysis further confirmed two major subpopulations with significant genetic divergence. These findings support the selective use of parent lines for hybrid rice breeding.
水稻中的温敏核雄性不育（TGMS）系对杂交育种至关重要，通过消除人工去雄和恢复基因的需求来增强遗传多样性。与需要特定恢复基因的细胞质雄性不育（CMS）系统不同，这些品系在高温下诱导不育，在低温下恢复育性。这种温度敏感机制使亲本系的配对具有更大的灵活性，增加了遗传多样性，并使杂种中有益性状能够重组。采用随机区组设计（RBD）并重复三次来评估这些TGMS水稻品系。本研究调查了TGMS水稻品系之间的分子多样性和遗传变异性。单株产量、每穗粒数、颖壳角度和花粉育性等性状表现出显著的表型和基因型变异，变异系数（PCV和GCV）、遗传力估计值以及遗传进展占均值的百分比（GAM）均较高，这些结果突出了显著的遗传变异和选择潜力。形态学数据的欧氏距离矩阵分析揭示了显著的遗传差异。TNAU 137S 1和TNAU 137S 2在遗传上最为相似，而TNAU 112S和TNAU 114S差异最大。主成分分析（PCA）揭示了TNAU 136S、TNAU 113S、TNAU 142S和TNAU 126S等品系之间不同的遗传特征，这些对杂交育种很重要。使用简单序列重复（SSR）标记的分子多样性分析鉴定出90个等位基因和8个遗传簇。贝叶斯分析进一步证实了两个具有显著遗传差异的主要亚群。这些发现支持在杂交水稻育种中选择性地使用亲本系。
