木薯寒冻害等级划分指标研究

目的]探索木薯寒害冻害等级划分的形态指标及方法。方法]开展室内人工模拟木薯寒害冻害试验。在极端低温0～4℃条件下处理1～3 d,置室内,7、20 d后观察。结果]茎杆芽眼死坏率和块根黑斑占切面比率均随温度的降低而增加,随低温持续时间延长而增加;茎杆干枯率不完全呈规律性变化;茎杆变色损伤率、髓部变色率及乳胶的量的变化率小或表现不明显。结论]茎杆芽眼死坏率适合作为木薯茎杆寒冻害等级划分形态指标;块根黑斑占切面比率适合作为木薯块根的寒冻害等级划分形态指标。同时,确定了木薯寒害冻害等级划分标准。

Study of Indicators of Freezing and Cold Injury Classification on Cassava

Objective] The morphological indicators and methods of freezing and cold injury classification on cassava were studied.Method] The artificial freezing and cold injury test on cassava was carried out.The indicators were obserred under the conditions of temperature 0-4 ℃ for 1-3 days and room temperature for 7 days or 20 days.Result] The stem bud death ratio and root discoloration rate were higher and higher as the temperature decreasing or time going.Stem dry ratio didn't always change with the treatment conditions.Stem discoloration rate,pith discoloration rate and amount of latex changed little with temperature decreasing and time going.Conclusion] Stem bud eye death ratio was suitable for morphological indicators of freezing and cold injury classification on stem.Root discoloration rate was suitable for morphological indicators of freezing and cold injury classification on root.Classification standard for cassava freezing and cold injury was defined.