Abstract:
【Objective】 This study aims to select the field maize hybrids for the identification of low temperature resistance,and the hybrids with strong low temperature resistance in the hope of providing variety reference for accurate early sowing and for evaluation and identification of low temperature resistance.
【Methods】 36 maize hybrids were selected as test materials.Under the real field environment, one normal temperature test and two low temperature tests were set up to investigate and measure the emergence potential, emergence rate, emergence index and average emergence time under low temperature and normal temperature conditions, and calculate the relative values.A total of 8 identification indexes of low temperature tolerance were obtained.Using the statistical methods of principal component analysis, cluster analysis and stepwise regression analysis, the evaluation indexes of low temperature seedling emergence tolerance were screened, and the comprehensive score was introduced to evaluate the low temperature seedling emergence tolerance of maize hybrids.
【Results】 With the decrease of temperature, the emergence rate, emergence potential and emergence index decreased, and the emergence time increased.Principal component analysis obtained that the cumulative contribution rate of the two comprehensive in dicators was 77.965%.Stepwise regression analysis established an equation and selected five key indicators, which could determine most of the variation of the comprehensive score
D value.Finally, based on
D-value cluster analysis, 36 hybrid varieties were divided into four categories, and 6 varieties with strong resistance to low temperature emergence were selected.
【Conclusion】 6 hybrids with strong low temperature tolerance were selected, which were Hangyan 58, Heyu 187, Xinyin KWS9384, Xinyin KWS3376, Huamei 1 and Fengtian 14.Five key indexes, including NEP, LEP, LER, NEI and LEI, were selected for efficient prediction and evaluation of low temperature emergence tolerance of maize hybrids.