Acta Agriculturae Zhejiangensis ›› 2023, Vol. 35 ›› Issue (4): 752-768.DOI: 10.3969/j.issn.1004-1524.2023.04.03

• Crop Science • Previous Articles     Next Articles

Effects of low temperature on seedling growth at sesame early seedling period and screening of low-temperature tolerant materials

ZHAO Yunyan1,2(), SUN Jian2, LIANG Junchao2, WANG Zhiqi2, YAN Tingxian2, YAN Xiaowen2, WEI Wenliang1,*(), LE Meiwang2,*()   

  1. 1. College of Agriculture, Yangtze University, Jingzhou 434025, Hubei, China
    2. Nanchang Branch of National Center of Oilcrops Improvement, Jiangxi Province Key Laboratory of Oilcrops Biology, Institute of Crops Research, Jiangxi Academy of Agricultural Sciences, Nanchang 330200, China
  • Received:2022-09-28 Online:2023-04-25 Published:2023-05-05

Abstract:

To study the effects of temperature on the growth and development of sesame seeds at the early seedling period, and analyze the physiological response to low temperature stress during sesame early seedling period and the differences in the responses of different genotypes of germplasm resources to low temperature stress. In this study, 5 sesame germplasms with different temperature sensitivities were used as the test materials, 5 treatment temperatures (28, 25, 21, 18, 15 ℃) were set for dark culture treatment, the root length, shoot length and seedling fresh weight were measured and analyzed to determine the sensitive temperature for low temperature stress during the early seedling preiod. The low-temperature tolerance of 188 sesame germplasm resources was evaluated by correlation analysis, membership function value and cluster analysis. In addition, we determined the physiological and biochemical indexes of different genotypes materials under low temperature tress at early seedling period. The results showed that with the decrease of temperature, root length, shoot length and fresh weight of sesame at early seedling stage showed a gradual downward trend, which decreased significantly at 18 ℃. The 188 sesame germplasm materials were clustered into 5 groups by cluster analysis, including 5 highly low-temperature resistant materials, 42 low-temperature resistant materials, 44 intermediately low-temperature resistant materials, 50 low-temperature intolerant materials and 47 extremely low-temperature intolerant materials. The results of geographical classification showed that there were certain differences in the low-temperature tolerance of test materials from different geographical sources, among which the low-temperature tolerance richness of central Jianghuai region was large. Under low temperature stress at early seedling stage, the physiological indexes of different genotypes of sesame shoot and root increased to different degrees, such as contents of H2O2, MDA, proline, soluble sugar and soluble protein, among which H2O2 and MDA contents increased significantly, and CAT and SOD activities increased. 5 highly low-temperature tolerant germplasm resources were screened out, such as Zhuzhi19 and Luozhi16, so as to lay a foundation for the exploration of low-temperature resistant sesame germplasm resources and the breeding of new varieties.

Key words: sesame, early seedling stage, low temperature stress, germplasm resource, genotype

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