The genetic behaviour of a yellow‐green leaf sweetpotato mutant, a269, was analysed to prepare for genetic mapping and cloning of this mutant and to elucidate the regulation of its molecular mechanisms. The phenotypic stability of the mutant was observed under natural conditions, and photosynthetic pigments in mature leaves were measured. GN1323 and a269 were crossed and backcrossed. Genetic behaviour was assessed using phenotypic expression and segregation in F₁, BC₁ and BC₂. The a269 leaves were yellow‐green at all stages after germination. The thylakoid lamellae of a269 were disorganized, had incomplete grana and were fewer compared with GN1323. The direct and reciprocal F₁ populations had normal leaf colour, whereas the BC₂ populations had yellow‐green leaves. Segregation of plants with normal‐ and yellow‐green leaf colour in the four BC₁ populations satisfied the backcross segregation ratio of 11 : 1 for auto‐allohexaploids. The a269 mutant is stable, and its trait is controlled by one recessive nuclear locus.

中文翻译：

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甘薯黄绿色叶片突变体a269的检查和遗传分析

对黄绿色叶片甘薯突变体a269的遗传行为进行了分析，以准备对该突变体进行遗传定位和克隆，并阐明其分子机制的调控。在自然条件下观察到该突变体的表型稳定性，并测量了成熟叶片中的光合色素。GN1323和a269进行了杂交和回交。遗传行为进行了表型表达和分离评估F ₁，BC ₁和BC ₂。在A269叶呈黄绿色，在发芽后的所有阶段。a269的类囊体薄片与GN1323相比，它们杂乱无章，格兰纳不完整，并且更少。直接和倒向的F ₁种群具有正常的叶子颜色，而BC ₂种群具有黄绿色的叶子。在四个BC ₁种群中，具有正常和黄绿色叶子颜色的植物的分离满足了自体六倍体的回交分离比为11：1。该A269突变是稳定的，它的特点是由一个隐性核基因控制。