关键词: 冬小麦, 品种筛选, 株型特征, 生理特征, 产量构成特征

Abstract:

【Objective】 The objective of this study was to provide simple detection indicators for the screening of stress resistant and widely adapted cultivars under the background of frequent meteorological disasters in the North HuangHuaiHai Plain, through to screen drought resistant, heat-resistant and cold resistant winter wheat cultivars, and to clarify the yield composition, plant type structure and physiological characteristics of stress resistant and widely suitable cultivars.【Method】A field and a greenhouse experiments (experiment 1 and experiment 2, respectively) were carried out in Gaocheng of Hebei province from Autumn 2017 to Summer 2020, and using 16 winter wheat cultivars as experimental material. For experiment 1, three treatments were set up, i.e., 0 irrigation, 1 irrigation (jointing) and 2 irrigation (jointing and flowering). For experiment 2, two treatments were set up at the late stage of filling, i.e., normal temperature treatment (CK) and warming temperature treatment. At the same time, the cold resistance test was conducted using the natural low temperature in the spring of 2018 and 2020. The stress resistance evaluation index, yield formation index, plant type structure index and leaf physiological index were determined.【Result】Five winter wheat cultivars were screened out by comprehensively considering yield, drought resistance index, yield heat sensitivity index and grade of freeze injury, and these cultivars included Jimai 23, Shannong 30, Jimai 325, Jimai 22 and Pinyu 8012. These cultivars had strong drought, heat and cold resistance, and had high and stable yield. By analyzing the correlation between yield and yield formation index, plant type index and leaf physiological index, it was found that 1000-grain weight, harvest index and biomass production were positively correlated with yield; the width of flag leaf, stem diameter and spike length were significantly or extremely significantly positively correlated with yield, while angle of stem and flag leaf was significantly negatively correlated with yield; relative chlorophyll value (SPAD value) and relative water content of flag leaf were positively correlated with yield, and the canopy temperature was negatively correlated with yield. Compared with other cultivars, the 1000-grain weight, harvest index and biomass production of the stress resistant cultivars increased by 12.9%, 5.2% and 3.4%, respectively. For stress resistant wheat cultivars, the width of flag leaf, angle of stem and flag leaf, diameter of basal stem, ear length and plant height were (16.2 ± 0.4) mm, (18.2 ± 3.2)°, (4.0 ± 0.3) mm, (7.5 ± 0.14) cm and (80.3 ± 1.3) cm, respectively. Compared with other cultivars, the SPAD value and relative water content in flag leaves of these five cultivars increased by 9.8% and 4.2% respectively, and the canopy temperature decreased by 1.9 ℃ at the late stage of filling.【Conclusion】The optimized plant type of the stress resistant wheat cultivars, namely “compact in the upper part and flat in the lower part”, was defined. The quantitative indexes were put forward, including width of flag leaf, angle of stem and flag leaf, diameter of basal stem and ear length; the physiological characteristics were put forward, including higher leaf SPAD value and relative water content of flag, and lower canopy temperature; the yield characteristics were identified, including higher 1000-grain weight, harvest index and biomass production.

Key words: winter wheat, cultivar selection, plant type characteristics, physiological characteristics, characteristics of yield components