Thus the leaves remain on the plant long after frost. So far N. H. :^541 

 has not produced viable seeds. It was selected primarily for its excellent 

 foliage. The flowers are of poor quality. 



N. H. :^5425 (Skinners Rambler x Yellow Pinocchio). Handsome glossy 

 foliage, rampant canes, and 25-petaled flowers of apricot color and hybrid 

 tea shape characterize this rose. The canes are not hardy at Durham, N. H. 

 without winter protection. The flowers are sterile, a condition typical of 

 offspring from crosses involving the diploid Skinners Rambler and tetra- 

 ploid hybrid tea varieties. Prepared slides of N. H. ^^5425 root-tips when 

 examined under the microscope revealed more or less equal numbers of 

 cells having 16, 17, 18, 19 and 21 chromosomes. The anticipated number was 

 21. Since it blooms but once in June, introduction as a named variety is 

 doubtful. 



N. H. :^5414 (open-pollinated seedling of White Mountains). A botanical 

 curiositv, this thick caned rose bears a few twice-compound leaves. The 

 canes are covered with bristles but lack all thorns. It has 14 chromosomes 

 in the root tips. 



N. H. #524 (Skinners Rambler x Betty Bland). Rosa blanda Ait. is a 

 thornless, extremely hardy species native to this area. Its genes were intro- 

 duced into a cross with Skinners Rambler through the use of the variety, 

 Betty Bland. Seedling N. H. :^524 is virtually thornless and has red canes 

 that are completely winter hardy. They are, however, subject to attack by 

 cane girdlers. The rather unattractive flowers have 29, small, magenta and 

 white-striped, irregular petals. The few seeds which have been produced 

 have failed to germinate. The leaves are dull, pale green and drop from 

 the canes early in the autumn. 



N. H. :^5314 (Skinners Rambler x Rosa virp;iniana) . A single seedling 

 resulted from this cross made in 1953. This seedling has all the taxonomic 

 features of the pollen parent, Rosa virginiana Mill, but has produced no 

 seeds. A single seedless fruit produced in 1957 was like those of Skinners 

 Ramb'er, the seed parent. Apparently no other visible characteristics were 

 inherited from the maternal parent and this is the only seedling of Skinners 

 Rambler that has inherited bush form in the Fj. Like both its parents, 

 N. H. 4^5314 has 14 chromosomes. Taxonomically, the pollen parent is typi- 

 cally 7?. virginiana but is a diploid. Most R. virgin'ana are tetraploid. 



Other Crosses Involving Skinners Rambler 



Skinners Rambler has repeatedly been pollinated by the Apple Rose, Rosa 

 pomifera Hermm. Only two seedlings have resulted. One of them, N. H. 

 #5246 has proliferated carpels within the double pink flowers. The other 

 seedling resembled a wild R. muh'flora Thunb. rose and from it an F2 

 population of 76 plants has been grown. All were similar to their parent 

 and showed no evidence of hybridi;^y involving the Apple Rose. 



The Apple Rose is one of the Caninae group which produces pollen bear- 

 ing seven chromosomes and egg cells having the seven mates plus 14 extra 

 chromosomes, thus giving the plants a somatic tetraploid number of 28. 

 Very different offspring would thus be expected from a cross in which the 

 Apple Rose was the seed parent than if it were the pollen parent. 



Another Caninae rose, Rosa eglanteria L., the Sweetbriar, has been used 

 in rose breeding to introduce genes for fragrant foliage. It is a pentaploid 

 species having a total somatic chromosome number of 35 but the pollen 



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