热带作物学报2018，Vol.39Issue(2)：260-266,7.DOI:10.3969/j.issn.1000-2561.2018.02.008
火龙果幼苗离体辐射诱变及其对低温胁迫的生理响应
Radiation Mutagenesis of Pitaya(Hylocereus undulatus Britt)Seedlings in vitro and Its Physiological Responces to the Low Temperature Stress
摘要
Abstract
To discuss the radiation mutagenesis of pitaya seedlings in vitro and its physiological reaction to low temperature stress,an experiment was carried out with aseptic plantlets induced from 'Zi Honglong' adult trees as the test materials to investigate the effect of 60Co γ-rays irradiation on the survival and growth of pitaya seedlings in vitro and its physiological responses to cold stress under selected pressure of 20 mmol/L HYP.The results showed that there was no significant effect of low irradiation dose(≤15 Gy)on the survival and differentiation of the seedlings in vitro.The survival and differentiation rate decreased significantly with the increase of irradiation does,and higher irradiation dose led to a more obvious effect.The feasible irradiation dose range determined by LD50 and LD40 for 60Co γ mutation was 38.5-42.4 Gy.Relative electrical conductivity (REC)and malonaldehyde (MDA)content of the seedlings increased with the time extending of low temperature,no matter using 60Co γ mutagens and 20 mmol/L HYP or not.There was a remarkable influence of low temperature on soluble sugar,soluble protein and proline,and all of them increased at first and decreased subsequently with the time of low temperature processing prolonged.Most changes of osmotic regulation substances completed in a relatively short period of time.All kinds of protective enzymes,including superoxide dismutase(SOD),peroxidase(POD),catalase (CAT)and ascorbate peroxidase(APX)activity changed inconsistently with the time extension of low temperature,and they were up to7.9％-61.5％,7.7％-47.1％,16.1％-28.4％ and 6.4％-63.7％,respectively,compared with the control.Most of the enzyme activity increased notably in the early stage of low temperature treatment,but declined gradually with the temperature decline and treating time prolongation.In a conclusion,the seedlings in vitro irradiated with 60Co γ,then selected with concentration of 20 mmol/L HYP,showed better cold hardiness under different treating time at 4 ℃ temperature in comparison with the control in the preliminary tests of physiological and biochemical indexes.关键词
火龙果/辐射诱变/低温胁迫/生理响应Key words
pitaya/radiation mutagenesis/low temperature stress/physiological response分类
农业科技引用本文复制引用
邓仁菊,范建新,王永清,杨芳锡,李顺雨..火龙果幼苗离体辐射诱变及其对低温胁迫的生理响应[J].热带作物学报,2018,39(2):260-266,7.基金项目
四川省“十二五”育种攻关专项资金项目(No.2011NZ0098-8) （No.2011NZ0098-8）
贵州省科研机构服务企业行动计划[黔科合服企(2015)4002号] （2015）
贵州省第五批创新人才基地建设(黔人领发[2016]22号). （黔人领发[2016]22号）
