汪端华 杨建国 李倩 吴双花 何长征 马艳青

摘 要： 南瓜银叶突变体48a是在嫩食型中国南瓜中分离筛选到的稳定遗传自交系，银色叶不仅可以作为标记性状应用到育种中，还可为南瓜抗虫、抗病、耐寒等一系列研究提供重要的材料基础。笔者对银叶突变体的表型特征及叶片的解剖结构进行鉴定分析，发现植株整体长势、熟性与野生型无明显差异;成熟叶片正面全部呈银灰色，叶绿素含量明显降低，叶片上表皮细胞与栅栏细胞间明显剥离，存在明显的空隙。利用突变体48a和野生型49a南瓜自交系构建的六世代遗传群体，调查发现F2的绿叶与银叶符合3∶1的分离比，回交群体BC1P1分离比符合1∶1，表明南瓜银色叶性状由单隐性基因控制。

关键词：南瓜; 银叶突变体; 表型特征; 遗传学分析

中图分类号：S642.1   文献标志码：A   文章编号：1673-2871（2020）04-012-05

Abstract： Pumpkin silver leaf mutant 48a is a stable genetic inbred line isolated from tender pumpkin （Cucurbita moschata Duch.），which can be used not only as a marker trait in breeding， but also provide a series of important information such as insect resistance， disease resistance， cold tolerance. In this study， the phenotypic characteristics of silver leaf mutants and the anatomical structure of the leaves were identified， and we found that there was no significantly difference on growth and maturity between mutant 48a and wild type， but the content of chlorophyll was significant decreased and a clear gap exsisted between the upper epidermal cells and the fence cells in mutant 48a. From analysis of the sixth-generations group builded by mutant 48a and wild-type， the result shows that F2 green leaves and silver leaves was 3∶1 separation ratio， and 1∶1 separation ratio between the backcross population BC1P1， indicated that silver leaf traits were controlled by single recessive gene.

Key words： Pumpkin; Silver leaf mutant; Phenotypic characteristics; Genetic analysis

南瓜葉片银斑是南瓜中的常见性状，主要表现为叶脉的腋处带银白色斑纹，俗称“银斑叶”，是受单个显性基因控制的一种斑纹[1-3]，区别于烟粉虱Bemisia tabaci B型（又名银叶粉虱B. argentifolii）诱发的葫芦科作物叶片正面全部呈银白色的银叶病[4-5]。2016年笔者在嫩食型中国南瓜资源中分离出1株完全银色叶突变体，自交后5代后形成可遗传的稳定银叶自交系，同时在同一材料中分离出稳定的普通绿叶自交系，田间种植观察发现银斑叶南瓜具有很好的避蚜和抗病毒病的效果，这为南瓜抗虫育种提供了新的思路。笔者对银叶突变体的表型特征、叶片解剖结构进行了鉴定分析，并构建了银叶六世代遗传群体进行遗传学分析，为后续的南瓜银色叶基因定位和避蚜上的应用奠定基础。……