雪花梨及其亲缘品种S基因型的确定

Identification of S-Genotypes in Xuehuali pear and its relative cultivars

梨是典型的自交不亲和性果树,自然授粉结实率低,品质差。通过确定梨品种S基因型可寻找简便快速克服自交不亲和性,提高产量,改良品质的方法。根据梨S基因的一级结构特点,利用S基因的保守序列设计特异引物,并对雪花梨及其亲缘品种的基因组DNA进行PCR扩增。将基因组特异扩增电泳只显示一条S基因带雪花梨的特异扩增片段回收并与T载体连接,转化至大肠杆菌中。取其中1个阳性克隆进行测序,并通过生物信息学软件分析确定其核苷酸序列,推导出氨基酸序列,经网上Blast比较,确定该雪花梨S基因片段的S基因型,然后就该S基因进行酶切系统分析,有针对性地挑取另一个阳性克隆测序分析。另外,通过品种间的亲缘关系并经过酶切检测以分析雪花梨亲缘品种的S基因型,并确定各品种的S基因型分别为:雪花S4S16、冀蜜S1S16、雪青S3S16、雪峰S4S16、雪英S3S16、雪芳S4S16。

Pear is the typical self-incompatibility fruit tree. Its yield is low and quality is bad under natural pollination conditions. The approach of overcoming self-incompatibility, increasing production and improving quality could be found through identifying pear S genotype. According to the basic structure characteristics of the Japanese pear S gene and its conservative sequence, specific primers were designed. Using the pair of primers, the DNA of Xuehuali pear cultivar and its relative species were carried on PCR. The specific bands of Xuehuali cuhivar displayed only one specific band after genome specific amplification was recaptured and connected with T-Vector, cloned. Sequencing one of the cloned bands and using bio-informatics software to analysis and identify its sequence and deducing the amino acids sequence, the S genotype of Xuehuali segment was identified. Then another enzymatic analysis aiming cloned band was sequenced and identified. Moreover, according to the relative relation and enzymatic action, the relative species S genotypes of Xuehuali were deduced. The S genotypes obtained were Xuehuali S4S16, Jimi S1S16, Xueqing S3S16, Xuefeng S4S16, Xueying S3S16, and Xuefang S4S16.