Studies On Wide Cross Breeding Of Roses (Ⅵ)

R. cvs. is one of the most famous ornamental plants in the world which have abundant cultivars, while a quite limited genetic background lead to the resistance of modern rose cultivars getting worse. Many wild species of Rosa have strong resistance traits, which has not been fully used. In order to breed new rose cultivars with strong resistance, modern roses were used as seed parents, while wild roses and some excellent hybrids of wild roses were pollen parents. The influence of parent’s sterility, genetic relationship and ploidy level on inter-specific cross compability was discussed. The main results were as follows:1. During 2013 to 2014, a total of 166 cross combinations were designed, and 2503 flowers were pollinated.109 hips and 785 mature hybrid seeds were obtained. The 20 hybridizations with affinity are: ‘Xue Shan Jiao Xia’× R. xanthina f. spontanea、‘Xue Shan Jiao Xia’x R. primula-.‘Xue Shan Jiao Xia’ x R. laxa,‘Palmengarten Frankfurt’בTian Shan Tao Yuan’、‘William Baffin’× R. laxa,‘William Baffin’× (‘Rainbow Knock out’× R. laxa)、‘La Sevillana’בXue Shan Jiao Xia’、‘La Sevillana’× R. xanthina f. spontanea、‘Autumn Sunset’× R. laxa、‘Watercolors’× R. primula、‘Watercolors’× R. xanthina f. spontanea、‘Watercolors’× R. laxa、‘Watercolors’בTian Shan Tao Yuan’、‘Watercolors’× ‘Tian Shan Zhi Guang’、‘Purple Heart’× R. primula、‘George Vancouver’×R. primula、‘George Vancouver’× R. xanthina f. spontanea、‘Lilac Rose’× R. xanthina f. spontanea、‘Lilac Rose’’x R. laxa、 ‘Fiona’× (R. canina‘Inermis’×R. primula).2.28 seedlings were obtained from hybrid seeds in 2014.3 seedlings of’George Vancouver’x R. primula,8 seedings of‘George Vancouver’× R. xanthina f. spontanea,2 seedlings of‘Xue Shan Jiao Xia’× R. laxa,1 seedling of‘Xue Shan Jiao Xia’× R. xanthina f. spontanea,2 seedlings of‘Purple Heart’× R. primula,9 seedlings of‘William Baffin’×R. laxa,3 seedlings of ‘La Sevillana’בXue Shan Jiao Xia’were obtained.3. Morphology, cytology, and SSR molecular markers were used in hybrid identification of 20 seedlings, and 17 plants were confirmed as real hybrids. Thus 2 seedlings of’George Vancouver’x R. xanthina f. spontanea,6 seedlings of’William Baffin’x R. Iaxa,1 seedling of’Xue Shan Jiao Xia’x R. laxa,2 hybrid seedlings of’La Sevillana’×’Xue Shan Jiao Xia’,1 hybrid seedling of’Rainbow Knock out’× R. laxa,1 hybrid seedling of R. canina’Inermis’x×R. primula and 4 hybrid seedlings of R. canina ’Inermis’× R. xanthina f. spontanea were identified as real hybrids.4. According to the result of hybrid identification, maternal parent’R. canina’Inermis" is pentaploid and paternal parents R. primula and R. xanthina f. spontanea are diploid. Hybrids were obtained from R. canina’Inermis’× R. primula and R. canina’Inermis’× R. xanthina f. spontanea. This provided a new way to gain hybrids when wide cross is between plants of different ploidies.