作 者：
邹士成;赵崇斌;王曼;白昀鹭;林顺权;何业华;吴锦程;杨向晖
单 位：
农业农村部华南地区园艺作物生物学与种质创制重点实验室;莆田学院·福建省高等学校重点实验室
关键词：
枇杷;果肉颜色;分子标记;PSY基因;遗传倾向
摘 要：
【目的】研究枇杷果肉颜色的遗传倾向。【方法】以黄肉品种‘梅花霞’和‘早钟6号’及白肉品种‘白玉’为亲本,创建了9个杂交和自交后代群体,利用SRAP和RAPD分子标记技术,鉴定真杂种。利用枇杷果实特异DNA分子标记PSY基因对9个杂交和自交组合后代的果肉颜色进行早期鉴定,并对其遗传倾向进行分析。【结果】9个杂交和自交后代群体中,共鉴定出1 166株真杂种‘。梅花霞’与‘白玉’和‘梅花霞’与‘早钟6号’的正反交组合后代未出现果肉颜色性状的分离倾向,果肉颜色均鉴定为黄色;而‘早钟6号’与‘白玉’的正反交组合后代果肉黄、白色的分离比分别为1∶0.89和1∶0.87。自交组合‘梅花霞’和‘白玉’的后代无果肉颜色性状的分离,后代果肉颜色分别鉴定为黄色和白色;而‘早钟6号’自交后代黄肉与白肉分离比例为2.94∶1。【结论】枇杷果肉颜色黄色和白色可能受到一对呈显隐关系的基因控制,其中黄肉性状为显性,存在纯合和杂合的情况,其分子标记类型不同,DNA分子标记分别表现为1 031 bp(纯合)或1 031 bp和319 bp(杂合);白肉性状为隐性,DNA分子标记为319 bp。
译 名：
Study on the inheritance of fruit color in loquat based on PSY gene marker
作 者：
ZOU Shicheng;ZHAO Chongbin;WANG Man;BAI Yunlu;LIN Shunquan;HE Yehua;WU Jincheng;YANG Xianghui;Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (South China) of Ministry of Agriculture;Putian University/Fujian Provincial key Laboratory of Colleges and Universities;
关键词：
Loquat;;Flesh color;;Molecular markers;;PSY;;Genetic inheritance
摘 要：
【Objective】Loquat(Eriobotrya japonica Lindl.), a genus of flowering plants in the Rosaceae family, has been cultivated in China more than 2 000 years. The carotenoid is the main pigment in loquat fruit, which leads to a difference in flesh color. Traditionally, loquat cultivars can be divided into two groups based on its flesh colors, that is, yellow-flesh and white-flesh. Compared with yellow-flesh cultivars, white-fleshed cultivars have become more popular because of their delicious flesh and higher economic value, and breeders also prefer to breed new white-flesh cultivars. However, the genetic mechanism of loquat flesh color is still unclear. Loquat breeding is limited at the seedling selection stage because of the long juvenile period. Therefore, it is very important to study the genetic inheritance of loquat flesh color. In this study, we analyzed the flesh color segregation ratio of different crossing combinations in order to study the genetic inheritance of loquat flesh color. Flesh color specific molecular markers were used to identify the flesh color of hybrid progenies at seedling stage.【Methods】Based on the specific molecular markers of loquat flesh color, there are two types of molecular markers in yellowflesh loquat cultivars: some yellow-flesh cultivars possess a long amplified fragment(1 013 bp), some possess two amplified fragment: a long fragment(1 013 bp) and a short fragment(319 bp). However,all white-flesh cultivars possess only a short amplified fragment(319 bp). Therefore, two types of yellow-flesh cultivars‘Meihuaxia’and‘Zaozhong No. 6’and one white-flesh cultivar‘Baiyu’were selected as parent materials in this study. Field crossing and selfing were carried out in 2017, and a total of 9 progeny populations were created, including 6 cross combinations and 3 selfing combinations.Among these progeny populations, the largest combination was‘Baiyu’בMeihuaxia’, the number of offsprings were 153; the small estprogeny came from the selfing of‘Meihuaxia’, the number of offsprings were 110. After sowing and seedling, the genomic DNA of each single plant of the 9 hybrid combinations was extracted and the RAPD and SRAP molecular markers were used to identify the true and false hybrids of the offspring. We found that 10 RAPD primers, 9 SRAP forward primers and 11 reverse primers could be used for further identification. Altogether 1166 offspring individuals were screened as true hybrids by RAPD and SRAP molecular markers and the average true hybrid rate was91.35%. The flesh color of each offspring of 9 progeny populations was identified using loquat flesh color specific DNA molecular markers at seedling stage, and their genetic inheritance was also investigated. Chi-square test was used to test whether the separation ratio of flesh color was in accordance with Mendelian’s law of heredity.【Results】The fruit flesh color segregation rations were different in different hybrid combinations. The hybrid combinations‘Meihuaxia’בBaiyu’and‘Baiyu’בMeihuaxia’did not show segregation in flesh color, the flesh color of their offsprings were all identified as yellow. The same results appeared in the hybrid combinations‘Meihuaxia’בZaozhong No. 6’and‘Zaozhong No. 6’בMeihuaxia’, their offsprings were all identified as yellow-flesh. However, the flesh color was obviously separated in the hybrid combination of‘Zaozhong No. 6’בBaiyu’and‘Baiyu’בZaozhong No. 6’, the separation ratios of yellow flesh and white flesh were 1:0.89 and 1:0.87, respectively. Their separation ratio was in accordance with Mendelian’s law of heredity. In the three selfing progenies of‘Meihuaxia’and‘Baiyu’there was no segregation on fruit flesh color, all offsprings of‘Meihuaxia’selfing were identified as yellow-flesh and all offsprings of‘Baiyu’selfing were identified as white-flesh. But, in selfing progeny of‘Zaozhong No.6’, the segregation ratio of yellow and white flesh was 2.94∶1, and its separation ratio wass also in accordance with Mendelian’s law of heredity.【Conclusion】For the first time, we used specific DNA molecular markers to study the separation of loquat flesh color from 9 different hybrid combinations. Our results showed that loquat flesh color was controlled by a pair of allel. The yellow flesh trait was dominant and white flesh trait was recessive. By the way, we could further distinguish the homozygous or heterozygous state of loquat yellow flesh trait using specific DNA molecular markers, the genetype of yellow-flesh was homozygous when the amplified band was a single long fragment(1 013 bp) and the DNA molecular markers were two amplified fragments(1 013 bp and 319 bp). The genotype of yellow-flesh was heterozygous. These results can provide a theoretical basis for the breeding of new loquat cultivars, especially for the breeding of the new white-flesh loquat cultivars.
