脱毒马铃薯田间再度罹病规律研究

脱毒马铃薯投放大田后重新感染病毒病.其重新罹病的程度、速率和大田连续种植代数、海拔高度等密切相关.在海拔2000m左右的地区,脱毒薯的有效种植年限至多为3代;当海拔升至2400～2700m,到第3代时,病情指数低于5%,可保持高产,若连续种植5～6代,则病情剧增,丰产性丧失;在海拔2800m的农区,重新感病速率接近于零.因此在高寒农区设置原种繁殖基地,并建立梯级循环繁种供种体系,是保持其高产势能的有效措施.

STUDY ON VIRUS FREED POTATO IS REINFECTED BY VIRUS IN FIELD OF QINGHAI

It is hard to avoid that virus freed potato is reinfected by virus after being applied in field.The degrew of infestation and velocity are closely corrlated with its years of growth,altitude levels etc.The virus freed potato shall be valid at most for 3rd generation where there is the areas with an elevation of 2 000 m.When the height rised to 2 400-2 700 m.The disease index is lower than 5% yet in 3-4th generations, and expects a good harvest of potato,but the highly yielding ability losed up to 5-6th generations, because of the infestation of virus increase in output.The potato on the areas with an elevation of about 2800 m.Are reinfected very light.Therefore, the original seed basic at the alpine area,and a mufti-level technical system of constant virus freed seed potato production and supply should be established for to ensure its high yield potential in field.