Identification S-genotypes And S-RNase Alleles On Chinese Cherry (Prunus Psedocerasus L.)

Gametophytic self-incompatibility is characteristic of many plants in the family Rosaceae, Chinese cherry (Prunus psedocerasus L.) is a allotetraploid species and exhibits natural self-compatibility, belonging to the genus Prunus. It originates from downstream of Yangtze River in China for thousands years and has many local cultivars. In Chinese cherry the S-RNase alleles and the molecular bases for self-compatibility are not clear. In this work, five Chinese cherry cultivars the S-genotypes were identified , full-length S-RNase cDNAs were cloned and the transcripts of S-RNases was studied to analyse the reasons of natural self-compatibility on Chinese cherry . The results were as follows:1. Of the six pairs of primers, the amplification effects of EM-PC2consFD + EM-PC3consRD, PruC2 + PCE-R , and Pa ConsⅠ-F + Pa ConsⅡ-R were much more better,So their were applicable for Chinese cherry S-RNase amplification.2. Five S alleles were cloned in five Chinese cherry cultivars using consensus primers EM-PC2consFD + EM-PC3consRD for Prunus S-RNase genes, The PCR bands were blasted in GenBank and named as S1-RNase (631bp), S2 -RNase (1432bp), S3-RNase (1186bp), S4-RNase (529bp) and S5–RNase (254bp), respectively. Their accession numbers in GenBank were EU038300-EU038304.3. Base on all the results of amplification using different primers, and the S-genotype of fivecultivars were identified, they were showed as follows: Tengxianhong ( S1S3S4 ); Daqingye ( S1S4S5 ); Dawolouye ( S1S3S4 );Taixiaohongying(S1 S2S3S4);Laiyang short cherry(S1 S2S3S4)。4. On the cultivars'Taixiaohongying'and'Laiyang short cherry'with S1S2 S3S4 genotypes, two full-length S-RNase cDNAs were cloned and named as S1–RNase(EU073938) and S2–RNase (EU073939).just like diploid sweet cherry(P. avium L.), the transcribed S1 and S2 alleles in the style have characteristic structure of Rosaceae S-RNases ,sequence character indicating that they have normal function for S-RNase. 5. Northern blot analysis showed that in the style S1–RNase and S2–RNase were transcribed, and no transcribed S3–RNase and S4–RNase were observed indicating that mutations occurr to S3–RNase and S4–RNase, and S3m and S4m can be used to represent the nonfunctional S3–RNase and S4–RNase, respectively. So the S-genotypes for'Taixiaohongying'and'Laiyang short cherry'can be written as S1S2S3mS4m .Based on all the analysis the two nonfuctional S3m–RNase and S4m-RNase may explain the self-compatibility of Chinese cherry.