桑树新品种农桑12号农桑14号的育成初报

A PRELIMINARY REPORT OF THE DEVELOPMENT OF TWO NEW MULBERRY VARIETIES──NONGSANG 12 AND NONGSANG 14

用人工有性杂交,单株选择,系统选择,区试鉴定,育成中熟桑树新品种农桑12号、农桑14号,与对照荷叶白相比,公顷桑叶产量高37.86%和41.36%,万头蚕产茧层量高8.38%和16.37%,区试鉴定结果公顷桑产叶量高46.44%和50.14%,万头蚕产茧层量高18.15%和19.56%,抗桑黄化型萎缩病和黑枯型细菌病力强,抗桑蓟马、红蜘蛛、桑粉虱能力强,生长势旺.可用扦插繁殖,农艺性状优良,适应性广.

Nongsang 12 and Nongsang14, two new medium - maturing varieties of mulberry, weredeveloped through the breeding processes of artificial sexual hybridization [Beiqu No. 1(Morus atropurpurea Roxb ) × Tongxiangqing (M. multicaulis perr) and Beiqu No. 1 ×Shishengsang No. 1 (M. multicaulis Perr)],single - plant and pedigree selection and region-al tests. In a reginal test, the two new varieties gave 37. 86% and 41. 36% higher annualleaf yield and 8. 38% and 16. 37% higher cocoon shell weight per 10, 000 silkworms ascompared with the control variety 'Heyebai'. In another regional test, their annual leafyield and cocoon chell weight per 10,000 silkworms were 46. 44% and 50. 14%, and18. 15% and 19. 56%, respectively, than those of the control. No yellow dwarf or blackbacterial wilt were observed in the plantation of the new varieties. They appeared to behighly resistant to mulberry thrip,mulberry whitefly and two - spotted spider mite, luxuri-ant and vigorous in growth and easy to multiply by cutting and to have desirable agronomiccharacters and wide adaptation.