广西甘蔗主栽品种梢腐病田间抗性初步评价

为更好地为广西甘蔗品种的合理布局和科学种植提供依据,探讨广西甘蔗主栽品种对梢腐病的田间抗性,根据发病程度,利用病情指数划分的抗性标准,在甘蔗梢腐病发生盛期,对目前广西蔗区13个主栽品种进行梢腐病抗性的田间综合评价。结果表明:宿根蔗感病程度比新植蔗严重。新植蔗表现为高抗的品种3个,抗病9个,中抗1个;宿根蔗表现为高抗的品种4个,抗病8个,中抗1个。综合不同蔗区新植蔗和宿根蔗的抗性表现,高抗品种2个(粤糖94-128、台优),抗病9个(ROC22、粤糖93-159、桂糖31、桂糖03-2287、桂糖42、台98-0432、桂糖29、柳城03-1137、桂糖21),中抗2个(柳城05-136、粤糖60)。新植蔗和宿根蔗抗性表现为同一水平的8个(粤糖94-128、台优、ROC22、桂糖03-2287、桂糖42、台98-0432、柳城03-1137、桂糖21),宿根蔗差于新植蔗的2个(桂糖31、粤糖60),3个变化趋势相反(粤糖93-159、桂糖29、柳城05-136)。不同蔗区梢腐病的发生情况不同,品种在各个蔗区的抗性表现也不同。2015年,广西蔗区主栽品种对梢腐病抗性达到中抗以上水平,说明梢腐病对该榨季广西甘蔗生产为害程度尚不严重。

Preliminary Evaluation of Resistance on Pokkah Boeng Disease of Major Sugarcane Varieties in the Field of Guangxi

This research aimed to provide scientific references for sugarcane distribution and planting via exploring the resistance difference on Pokkah boeng disease of major sugarcane varieties in the field of Guangxi. The resistance to Pokkah boeng of 13 major sugarcane varieties in Guangxi were comprehensively evaluated according the incidence and disease severity index(DSI)during the epidemic period in the field. The results showed that the ratoon cane was more susceptible than new-planting. Three varieties were graded high resistance(HR), 9 were resistance(R), and one was moderate resistance(MR)in new-planting, and the number of HR, R, MR were 4, 8, 1 respectively in the ratoon cane. Comprehensive evaluation of the resistance of the varieties in new-planting and ratoon, two varieties of YT94-128 and Taiyou were graded the HR level, 9 varieties including ROC22, YT93-159, GT31, GT03-2287, GT42, Tai98-0432, GT29, LC03-1137 and GT21 were graded the R level, whereas LC05-136 and YT60 were graded the MR level. Resistance levels of 8 varieties in new-planting were the same with that of ratoon, including YT94-128, Taiyou, ROC22, GT03-2287, GT42, Tai98-0432, LC03-1137 and GT21, GT31 and YT60 varieties in ratoon were more susceptible than new-planting, but 3 varieties of YT93-159, GT29 and LC05-136 showed the opposite. The results indicated all of the major varieties of Guangxi expressed MR or higher to Pokkah boeng disease in 2015, and the disease was not serious in 2015-2016 crushing season.