| Potato wild species have many biotic and abiotic resistance genes,but there is cross-incompatibility between the wild species and the cultivated species as the result of the difference in Endosperm Balance Number(EBN)and ploidy.Protoplast fusion is a good solution to this problem by overcoming the barrier of sexual hybridization.Previously,93 somatic hybrids were obtained by protoplast fusion with S.etubersoum and AC142;51 somatic hybrids were obtained by protoplast fusion with S.commersonii and AC142.The ploidy,agronomic characters and pollen vigor of EA somatic hybrids were identified.The ploidy and cold resistance of MA somatic hybrids were identified.S.etubersoum is a diploid wild non-tuberous species and has many virus resistance.S.commersonii is a diploid potato wild species.AC142 is a diploid material which has tuber.For all the somatic hybrids obtained from fusion,their information is unknown.In order to make better use of these materials,their basic characteristics need to be analyzed.A total of 37 somatic hybrids(tetraploid and hexaploid)were selected for the identification of virus resistance and tuberization.At the same time,the cytoplasmic composition of S.etuberosum + AC142 somatic hybrids and S.commersonii + AC142 somatic hybrids was analyzed.The main results were as follows:1 Cytoplasm composition: The cytoplasmic origin of somatic hybrids was analyzed using chloroplast and mitochondrial specific primers.Cluster analysis of amplified fragments of somatic hybrids showed that partial somatic hybrids follow recombination of mitochondrial genome from both parents,and chloroplast pattern from only one parent.The chloroplast composition of EA somatic hybrids was obviously biased to AC142;The MA somatic hybrids were different,and their chloroplast types had no obvious bias.2 Identification of virus resistance in EA somatic hybrids: By inoculating with the virus,resistant materials were screened from 37 somatic hybrids.Seven PVY resistant lines,EA7-3,EA11-1,EA48-1,EA56-1,EA92-1,EA55-1,and EA28-1.Eight PVS resistant lines,EA48-1,EA56-1,EA92-1,EA5-1,EA49-1,EA53-1,and EA88-1.Two PVX resistant lines: EA11-1 and EA40-1.The fusion parents were resistant to PVA,so all somatic hybrids also had PVA resistance.3 Phenotype identification of tuberiation in EA somatic hybrids: The tuber formation of somatic hybrids was analyzed in greenhouse in the first half of 2016 and the second half of 2016,respectively;The experiment of microtuber was carried out in culture room.The results of three experiments showed that all tetraploid hybrids could produce tubers,but tubers were small,and there was no significant difference between tetraploid hybrids and non-tuberous hybrids in weight.There were significant differences among hexaploid somatic hybrids: Tuber or not.Some somatic hybrids had significantly higher weight than their parents.Correlation analysis showed that the highest consistency was observed in two greenhouse tuber experiments,The second is the correlation between the microtuber and the first half of the greenhouse,but the second half of the greenhouse has no correlation with the microtuber. |
