摘要:

SUMMARYSeedlings of two susceptible sugar‐beet stocks were grown either in daylight or in darkness for 24 h before or after inoculation withPeronospora farinosaf.sp.betae. Post‐inoculation darkness did not significantly affect the percentage of inoculated plants that became infected but increased the percentage of plants on which the fungus sporulated in both stocks. The effects on sporulation of darkness before inoculation were more variable than those of post‐inoculation darkness.In the same stocks removal of all leaves, except those in the bud, before inoculation increased the percentage both of plants which became infected and of those on whichP. farinosasporulated. Infection and sporulation were not significantly affected by defoliation in a more resistant stock.Defoliation or darkness may have affected the concentration of certain sugars or amino acids in the bud leaves thereby changing the expression of polygenically‐controlled resistance to downy

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb04692.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1972.tb04693.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY