桑树新品种农桑12号、农桑14号的育成

通过人工有性杂交、单株选择、系统选择、区试鉴定 ,育成早生中熟桑树新品种农桑 12号、农桑 14号。 2个新品种分别比对照种荷叶白每公顷桑叶增产 39 2 6 %和 44 0 1% ,万蚕茧层量高 12 84%和 12 70 % ,在自然种植桑园中 ,桑黄化型萎缩病、桑黑枯型细菌病、桑蓟马、红蜘蛛等的为害明显轻于对照。新品种生长势旺 ,可扦插繁殖 ,农艺性状优良 ,适应性广 ,已通过全国和浙江省农作物品种审定

Breeding of New Mulberry Varieties-Nongsang 12 and Nongsang 14

The early sprouting and mid maturing new mulberry varieties Nongsang 12 and Nongsang 14 were bred through hybridization,single plant selection,pedigree selection and regional test.The yield of mulberry leaves per hm 2 of two new mulberry varieties increased by 39.26% and 44.01% respectively compared to Heyebai.The cocoon shell weight of 10 000 silkworms reared with the newly bred varieties were 8.03% and 6.12% higher than that of the control respectively.The damage caused by yellow dwarf disease,black bacterial blight,Pseudodendrotrips mori Niwa and the two spotted spinder mite Tetranychus urticae Koch on the new varieties were all significant lower than that of the control.The two new mulberry varieties also have other good characteristics such as vigorous growth,higher rooting power and wildly adaptability.They have been approved by National and Zhejiang Crop Variety Evaluation Commissions.