AFLP markers closely linked to a major gene essential for nucellar embryony (apomixis) in Citrus maxima x Poncirus trifoliata
AFLP markers closely linked to a major gene essential for nucellar embryony (apomixis) in Citrus maxima x Poncirus trifoliata
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DOI：
10.1007/s11295-009-0223-z
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发表时间：
2010-12-01
影响因子：
2.4
通讯作者：
Roose, M. L.
中科院分区：
文献类型：
--
作者：
Kepiro, J. L.;Roose, M. L.
一些柑橘品种表达一种称为珠心胚的无融合生殖形式，其中不定胚由胚囊周围的珠心组织发育而成。这种特性导致许多种子含有多个胚胎（多胚）。对88个大柑（单胚）×枳（多胚）杂交后代的多胚发生频率进行了遗传研究。通过对100-500粒种子从每粒种子中发芽的幼苗数量进行评分来确定每粒后代产生的多胚种子的频率。用256对引物组合扩增出的扩增片段长度多态性标记，从群体的每个极端选择两组8个个体进行混合分离分析。在用于产生批量的32个个体上测试批量中鉴定为与性状相关的候选标记，然后在群体中的剩余植物上测试。筛选出5个与三叶草多胚性紧密连锁的候选标记。特异性标记等位基因存在于几乎所有产生多胚种子的后代中，并且交替等位基因存在于几乎所有仅产生单胚种子的后代中。由这些标记所定义的区域很可能包含一个基因，该基因对于通过无融合生殖产生多胚种子是必需的，但也显示出分离畸变。多胚种子的比例在杂种后代中变化很大，可能是由于其他基因。通过对119个三叶草自交群体后代的多胚种子比例和紧密连锁标记的分析，证实了这些标记与多胚性之间的紧密连锁。
Some citrus varieties express a form of apomixis termed nucellar embryony in which the adventive embryos develop from nucellus tissue surrounding the embryo sac. This trait results in many seeds containing multiple embryos (polyembryony). Inheritance of the frequency of polyembryony was studied in 88 progeny from a cross of Citrus maxima (monoembryonic) x Poncirus trifoliata (polyembryonic). The frequency of polyembryonic seed produced by each progeny was determined by scoring 100-500 seeds for the number of seedlings to emerge from each seed. Two groups of eight individuals from each extreme of the population were chosen for bulked segregant analysis with amplified fragment length polymorphism markers amplified with 256 primer combinations. Candidate markers identified in the bulks as linked to the trait were tested on the 32 individuals used to create the bulks and then on the remaining plants in the population. Five candidate markers tightly linked to polyembryony in P. trifoliata were identified. Specific marker alleles were present in nearly all progeny that produced polyembryonic seed, and alternate alleles were present in nearly all progeny that produced only monoembryonic seed. The region defined by these markers very likely contains a gene that is essential for the production of polyembryonic seeds by apomixis, but also shows segregation distortion. The proportion of polyembryonic seeds varied widely among the hybrid progeny, probably due to other genes. Scoring 119 progeny of a P. trifoliata selfed population for the closely linked markers and the proportion of polyembryonic seeds confirmed close linkage between these markers and polyembryony.