Georgiady Michael S, Whitkus Richard W, Lord Elizabeth M
Department of Botany and Plant Sciences, University of California, Riverside, California 92521.
Genetics. 2002 May;161(1):333-44. doi: 10.1093/genetics/161.1.333.
The evolution of inbreeding is common throughout the angiosperms, although little is known about the developmental and genetic processes involved. Lycopersicon pimpinellifolium (currant tomato) is a self-compatible species with variation in outcrossing rate correlated with floral morphology. Mature flowers from inbreeding and outcrossing populations differ greatly in characters affecting mating behavior (petal, anther, and style lengths); other flower parts (sepals, ovaries) show minimal differences. Analysis of genetic behavior, including quantitative trait locus (QTL) mapping, was performed on representative selfing and outcrossing plants derived from two contrasting natural populations. Six morphological traits were analyzed: flowers per inflorescence; petal, anther, and style lengths; and lengths of the fertile and sterile portions of anthers. All traits were smaller in the selfing parent and had continuous patterns of segregation in the F(2). Phenotypic correlations among traits were all positive, but varied in strength. Quantitative trait locus mapping was done using 48 RFLP markers. Five QTL total were found involving four of the six traits: total anther length, anther sterile length, style length, and flowers per inflorescence. Each of these four traits had a QTL of major (>25%) effect on phenotypic variance.
近亲繁殖现象在整个被子植物中很常见，尽管人们对其中涉及的发育和遗传过程知之甚少。醋栗番茄（Lycopersicon pimpinellifolium）是一种自交亲和的物种，其异交率的变化与花的形态相关。自交和异交群体的成熟花在影响交配行为的特征（花瓣、花药和花柱长度）上有很大差异；其他花部（萼片、子房）差异极小。对来自两个形成对比的自然群体的代表性自交和异交植株进行了包括数量性状位点（QTL）定位在内的遗传行为分析。分析了六个形态性状：每花序花数、花瓣长度、花药长度、花柱长度以及花药可育和不育部分的长度。所有性状在自交亲本中都较小，并且在F(2)代中呈现连续的分离模式。性状间的表型相关性均为正，但强度各异。使用48个RFLP标记进行了数量性状位点定位。总共发现了5个QTL，涉及六个性状中的四个：花药总长度、花药不育长度、花柱长度和每花序花数。这四个性状中的每一个都有一个对表型变异有主要（>25%）影响的QTL。
