黄瓜耐低温突变体材料的筛选与鉴定

[目的]本文旨在筛选耐低温的黄瓜突变体，丰富黄瓜耐低温资源材料。[方法]对1 818份‘长春密刺’黄瓜突变体材料进行13℃低温发芽试验，通过比较相对发芽率和胚根生长情况，初步筛选耐低温材料。进一步对筛选出的幼苗进行低温处理（15℃/7℃，昼/夜12 h/12 h，10 d），测定并分析其冷害指数、形态指标、电导率、丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。[结果]根据13℃低温发芽试验，将突变体材料分为耐低温型、中间型和冷敏型。其中，耐低温材料共22份，占总材料的1.21%。苗期4项形态指标表明筛选出的耐低温突变体材料在低温胁迫下的整体长势优于对照，并且耐低温材料的冷害指数、电导率、MDA含量和SOD活性也显著低于对照。综合比较后最终鉴定出7份耐低温材料。[结论]通过筛选突变体可以获得耐低温新材料，这些材料的获得对于黄瓜耐低温性状的遗传研究和新品种的培育具有重要的意义和价值。
[Objectives] This article aims to broaden the cold tolerant materials of cucumber. [Methods] The 1 818 ‘Changchunmici’ cucumber mutants materials were preliminarily screened to obtain the candidate cold tolerant lines based on the relative germination rate and radicle growth under 13℃. Further,these lines were treated with 15℃/7℃ in day/night 12 h/12 h for 10 days at seedling stage. Then chilling injury index and morphological indicators were investigated and some physiological index,electrical conductivity,MDA content and SOD activity were analyzed. [Results] According to germination test under 13℃,mutants were divided into tolerant type,middle type and sensitive type. Among them,22 mutants were tolerant type,accounting for 1.21% of the total materials. Under low temperature stress,four morphological indexes of seedling stages indicated that selected cold tolerant mutants grew better than ‘Changchunmici’ and these mutants had a lower value of chilling injury index,electrical conductivity,MDA content and SOD activity than ‘Changchunmici’. Based on the results,7 cucumber lines with tolerance to cold stress were finally identified. [Conclusions] Cold tolerant materials can be obtained from mutants,and these materials will be valuable for the research of chilling tolerance gene and future cucumber breeding