Heat stress is an important abiotic stress affecting the productivity of tomato. Understanding the physiological basis of heat tolerance is needed to adapt to the current or future heat stress. Thus this study was undertaken to evaluate the phenology, physiology, biochemical and yield parameters of twenty-two contrasting tomato accessions when exposed to high temperature stress and to identify SSR markers associated with these traits. The experiment was laid out in completely randomized design with two treatment levels i.e. control and high temperature stress (36 ± 2 °C) with three replications each. The high temperature stress was induced from flower initiation to maturity stage by keeping the pots in a temperature controlled green house facility for 45 days. Twenty five SSR primers were employed to analyze genetic diversity and population structure among 22 tomato accessions collected from different eco-geographical regions of India. SSR markers proved to be more informative in genetic diversity assessment. These accessions showed significant genetic variability for physio-morphological and yield traits under both control and high temperature condition. Clustering by average linkage method was done to establish a relationship among the 22 tomato accessions. All the accessions were clustered into mainly three clusters. Principle component analysis revealed that, the first principal component revealed 43.39 per cent variation, while the second component showed 12.93 per cent variation under high temperature condition. Principle co-ordinate analysis evidently differentiated the accessions to three main groups based on genetic relatedness. Population structure analysis also obviously separated the accessions to four sub populations.GLM analysis identified 10, 9 highly significant marker traits association under high temperature and control condition respectively. Among them, RM270, SSR605 and RM356 were linked to more than one traits. Identified tolerant accessions and molecular markers can be utilized for developing high yielding high temperature tolerant tomato varieties in breeding programmes.

热应激是影响番茄产量的重要非生物胁迫。需要了解耐热性的生理基础以适应当前或未来的热应激。因此，本研究旨在评估暴露于高温胁迫下的 22 个对比番茄品种的物候学、生理学、生化和产量参数，并确定与这些性状相关的 SSR 标记。该实验采用完全随机设计，有两个处理水平，即对照和高温胁迫 (36 ± 2 °C)，每个水平重复 3 次。通过将盆放在温控温室设施中 45 天，诱导从开花开始到成熟阶段的高温胁迫。采用 25 个 SSR 引物分析从印度不同生态地理区域收集的 22 个番茄种质的遗传多样性和种群结构。SSR 标记被证明在遗传多样性评估中提供更多信息。这些种质在控制和高温条件下的生理形态和产量性状均显示出显着的遗传变异性。通过平均连锁法进行聚类以建立 22 个番茄种质之间的关系。所有的种质主要分为三个簇。主成分分析表明，第一主成分在高温条件下的变化率为43.39%，而第二主成分在高温条件下的变化率为12.93%。原则坐标分析明显区分了基于遗传相关性的三个主要群体的种质。群体结构分析也明显区分了4个亚群的种质。GLM分析分别在高温和对照条件下鉴定出10个、9个高度显着的标记性状关联。其中，RM270、SSR605和RM356与不止一种性状有关。鉴定的耐受性种质和分子标记可用于在育种计划中开发高产耐高温番茄品种。其中，RM270、SSR605和RM356与不止一种性状有关。鉴定的耐受性种质和分子标记可用于在育种计划中开发高产耐高温番茄品种。其中，RM270、SSR605和RM356与不止一种性状有关。鉴定的耐受性种质和分子标记可用于在育种计划中开发高产耐高温番茄品种。