长林无性系油茶抗旱性的综合评价

Comprehensive evaluation of drought tolerance for Camellia oleifera Changlin clones

关键词:  干旱胁迫, 抗旱系数, 相关性分析,主成分分析, 权重

Key words:  drought stress, drought resistance coefficient, correlation analysis, principal component analysis, weight

摘要:

油茶产区在夏季常伴有持续干旱、高温少雨等天气,造成油茶产量不高。为了解持续干旱对油茶生理造成的影响,该研究以两年生的9个长林无性系油茶为材料,在温室内模拟自然干旱胁迫试验,并研究干旱胁迫第0、5、10、15、20和25天时其叶片生理生化指标的变化。同时以各生理指标的抗旱系数作为衡量油茶抗旱性的指标,利用主成分分析、隶属函数法及权重对其抗旱能力进行综合评价。结果表明:将14个单项指标降维成3个独立的综合指标,并通过隶属函数值和权重确定各油茶耐旱性综合评价值,进而得到长林无性系油茶的抗旱强弱依次为长林59号>长林22号>长林53号>长林4号>长林40号>长林8号>长林3号>长林27号>长林18号。

Abstract:

In summer, it is often high temperature and drought result in low yield of Camellia oleifera in C. oleifera plantation. Water defect will reduce the plant photosynthesis with consequent low yield of plants. However, there is little information on the drought stress physiological research of C. oleifera. In order to study the effects of physiology of C. oleifera under constantly drought stress, the 2-year-old seeding of C. oleifera Changlin clones were cultured in pots(30 cm × 30 cm × 25 cm)in greenhouse. There were two water stress treatment groups named respectively control group and drought stress group in this study. The drought stress group suffered from persistent irrigation water deficit, while the control group cultivated under normal irrigation condition. Subsequently, the change of physiological and biochemical indices of leaves including reactive oxygen species contents, antioxidant enzyme activities, osmotic substances contents, cell membrane permeability and photosynthesis were measured on 0, 5, 10, 15, 20 and 25 d after drought stress in order to screen C. oleifera of strong resistant of environmental stress. In this study, the different drought resistance coefficients of C. oleifera such as superoxide anion radical(O^-₂·)content, hydrogen peroxide(H₂O₂)content, the activities of peroxidase(POD), catalase(CAT)and superoxide dismutase(SOD), the relative electric conductivity, proline content(Pro), chlorophyll content, net photosynthetic rate(Pn), stomatal conductance(Gs), transpiration rate(Tr)and water use efficiency(WUE)were as drought tolerance indices. Finally, the comprehensive evaluation of drought resistance coefficients of C. oleifera physiological indices was performed with correlation analysis, principal component analysis, subordinative function and weight. The result indicated that 14 indices could be classified into 3 independent comprehensive components, and then utilized the value of weight and subordinative function to perform the values of comprehensive evaluation of different Camellia varieties. According to the value of different comprehensive evaluation value, the order of drought-resistance of nine C. oleifera Changlin clones was “Changlin59” > “Changlin22” > “Changlin53” > “Changlin4” > “Changlin40” > “Changlin8” > “Changlin3” > “Changlin27” > “Changlin18”. The results extensively provide certain scientific basis for breeding, introduction and cultivation of drought-tolerant Camellia varieties in Sichuan.