Hybrids Between Eriobotrya Japonica And Eriobotrya Bengalensis And Their Offsprings Identification By Leaf Morphology And ISSR

The distant hybridization is one of the important ways of improving varieties. In the present study, cultivated loquat (Eriobotrya japonica Lindl. cv.’Dawuxing’and4-1-5) and wild loquat(Eriobotrya bengalensis Hook. F.) were used for interspecific hybridization and their offsprings were identified by ISSR (inter-simple sequence repeat) and leaf morphological characteristics in early stage. The purpose of the study was to transfer special characters of bengal loquat (such as blooming in spring) into loquat, thus in-depth modifying loquat.The main results are as follows.1. A short-term (a month) storage was carried out using pollens of’Dawuxing’loquat. The longer drying time, the lower pollen initial vitality. Low temperature was helpful to pollen short-term storage, while pollen lost vitality quickly at nomal temperature. Loquat pollen vitality reached a satisfactorilly high vitality (67.60%) in the treatment of drying2h or3h, storage at4℃. The best result (72.77%vitality) was obtained in the treatment of drying4h or5h and storage at-20℃.2. Secrete mucus and the stigma receptivity increased and then reduced from childhood to petal fall, reaching the highest level in the fourth stage,which kept pace with pollen dispersal. The stigma receptivity sustained longer time. Loquat flower construction was suitable for self-pollination.3. Fluorescence detection revealed that the pollen tube formed after pollination6h and about90%of pollen germinated on stigma; the pollen tubes broke papilla through the top of stigma; pollen tubes reached the middle of stigma after pollination24h and about three-quarters of the pollen tubes reached near to the bottom of stigma after pollination48h. Loquat and bengal loquat were of good compatibility. No significant difference was seen in direct cross and reciprocal cross between loquat and bengal loquat.4. Parental combination, bud stage and pollination position significantly or highly significantly influenced setting percentage. Pollination on small bud and crown periphery was helpful to improving hybrid setting percentage. 5. Two optimal primers UBC895and UBC899were used in PCR amplification of50materials including parents.261and275DNA bands were amplified, in which215and225DNA bands were polymorphic, accounted for82.4%and81.8%of the total number, and on the average each material generated4.3and4.5polymorphic bands, respectively, showing good polymorphism.6. Primer UBC895amplified a specific band of’Dawuxing’loquat and bengal loquat, and22of23offsprings were identified true hybrids, hybrid rate reaching95.7%,while primer UBC899amplified three specific bans from’Dawuxing’loquat, and20of23offsprings were identified true hybrids, hybrid rate reaching87.0%.19of23offsprings were identified true hybrids by two primers. Primer UBC895amplified a specific band of4-1-5loquat and bengal loquat also, and19of24offsprings were identified true hybrids, hybrid rate was79.2%, while primer UBC899amplified three specific bands from4-1-5loquat, all offsprings were identified true hybrids, hybrid rate was100%.19of24offsprings were identified true hybrids by two primers. Most characters of hybrids were described between parents in leaf morphology, and tended to female parents.Combining ISSR with leaf morphology,10and9true hybrids were obtained in the direct cross and reciprocal cross between’Dawuxing’loquat and bengal loquat respectively, and11and8true hybrids in the direct cross and reciprocal cross between4-1-5loquat and bengal loquat. In other words,21true direct cross hybrids and17true reciprocal cross hybrids of loquat and bengal loquat were obtained at last. These hybrids could be valuable for follow-up research.