A short ripening stage, multiple large seeds per fruit, and anthracnose disease seriously restrict the loquat (Eriobotrya japonica) industry. To obtain breeding germplasm of loquat with multiple ideal traits, a wild Eriobotrya species, E. cavaleriei (2n=2x=34), which flowers in late spring and early summer and whose fruits ripen in autumn, was used as the male parent to produce triploid plants from crosses with loquat tetraploid (2n=4x=68) lines (EjK474, EjB433 and EjB456). Fifteen progenies were obtained from three hybridizations, and 13 plants were identified as hybrids according to insertion-deletion (InDel) markers. All 13 hybrids were roughly identified as triploids by flow cytometry. Therein, 4 plants were identified as aneuploids with decreased or increased chromosome numbers based on sequencing depth according to reduced-representation genome sequencing. The sequencing depth on some chromosomes of these 4 hybrids was approximately 2/3 times or 1.41 times the average depth of all detected InDel loci. Frequencies of the loquat parent-specific alleles on increased or decreased chromosomes were approximately 50% or 75%. This verified that increased or decreased alleles in the 4 hybrids were all from tetraploid parents. The fruit flesh color genotypes of all hybrids were detected; there were two red-flesh alleles and one white-flesh allele in all hybrids. Leaves of E. cavaleriei were highly resistant to anthracnose in an in vitro assay, and the leaves of loquat B433 were sensitive. Disease spot diameters on the leaves of hybrids were significantly smaller (p < 0.01) than those of B433 after infection by spores of C. gloeosporioides. Therefore, the resistance of the hybrids was greater than that of the female parent B433. All these results showed that allotriploids can be obtained via hybridization between loquat tetraploids and E. cavaleriei, with some aneuploids as secondary products. Different flowering phases and fruit ripening stages, seedlessness and resistance to anthracnose might be combined in allotriploids. This study verified that resequencing can be used to identify the molecular karyotype of interspecific hybrids.

熟期短、单果多粒大、炭疽病严重制约枇杷产业发展。为获得具有多种理想性状的枇杷育种资源，野生枇杷属E. cavaleriei(2n=2x=34)，春末夏初开花，秋季果实成熟，作为父本与枇杷四倍体(2n=4x=68)品系杂交产生三倍体植株(EjK474, EjB433)和 EjB456)。3次杂交共获得15个子代，根据插入-缺失（InDel）标记，13株植株被鉴定为杂种。通过流式细胞术，所有 13 个杂种都被粗略地鉴定为三倍体。其中，根据简化代表性基因组测序，基于测序深度，4株植物被鉴定为具有减少或增加的染色体数目的非整倍体。这 4 个杂交体的部分染色体的测序深度大约是所有检测到的 InDel 位点平均深度的 2/3 或 1.41 倍。增加或减少的染色体上枇杷亲本特异性等位基因的频率约为 50% 或 75%。这验证了4个杂种中增加或减少的等位基因均来自四倍体亲本。检测了所有杂交种的果肉颜色基因型；所有杂交种均有2个红肉等位基因和1个白肉等位基因。的叶子E. cavaleriei在体外试验中对炭疽病具有高度抗性，而枇杷 B433 的叶子是敏感的。在被胶孢孢子虫孢子感染后，杂交种叶片上的病斑直径明显小于 ( p  < 0.01) B433 。因此，杂种的抗性大于母本B433。这些结果表明，通过枇杷四倍体与E. cavaleriei杂交可以获得异源三倍体，一些非整倍体作为次级产品。不同的开花期和果实成熟期、无籽和对炭疽病的抗性可能在异源三倍体中结合。本研究证实重测序可用于鉴定种间杂种的分子核型。