柑橘天然杂种秭归橘橙来源探究

Exploring the origin of natural citrus hybrid Zigui Tangor

秭归橘橙为天然柑橘杂种,果实无核、早熟,但其亲本来源未得到深入的分析和验证。为探明秭归橘橙的亲本,应用倍性检测、形态学标记和AFLP、cpSSR、nSSR等分子标记,对其进行遗传鉴定。倍性检测证实秭归橘橙为二倍体,叶形指数、气孔密度和大小、花粉育性和花粉形态分析表明秭归橘橙形态特征上偏向于甜橙,而其花粉染色活力介于甜橙与红橘之间。AFLP聚类分析表明秭归橘橙介于橙和橘之间。cpSSR、nSSR确认秭归橘橙的母本为甜橙(Citrus sinensis[L.]Osbeck),父本为橘类(C.reticulate Blanco)。

Zigui Tangor is a seedless, natural early season citrus hybrid with unconfirmed origin. This study is to clarify the possible parentage of Zigui Tangor via ploidy analysis, morphological markers, and molecular markers including amplified fragment length polymorphism （AFLP）, chloroplast simple sequence repeat （cpSSR） and nuclear simple sequence repeat （nSSR）. Ploidy analysis confirmed that Zigui Tangor was a diploid. Analysis of morphological traits including phylliform index, stoma shape, pollen stain ability and pollen shape with scanning electron microscopy （SEM） indicated that the morphology of Zigui tangor was inclined to the sweet orange, while its pollen stain ability was between the sweet orange＇ s and the tangerine＇ s. The AFLP clustering results showed that Zigui tangor was located between the sweet orange and the tangerine. cpSSR and nSSR clearly showed that its female parentage was the sweet orange [Citrus sinensis （L.） Osbeck] and its male parentage was the tangerine （Citrus reticulata Blanco）.