Articles
EXPRESSION OF POWDERY MILDEW RESISTANCE IN F1 PROGENIES AND HOST-PATHOGEN INTERACTION IN CUCUMBER
Article number
588_22
Pages
149 – 153
Language
English
Abstract
The expression of powdery mildew resistance (PMR) genes in F1 and the nature of the host-pathogen interaction were studied under two different temperature conditions using three different types of cucumber cultivars.
When PI197088-5 (Type 1) showing PMR irrespective of temperature condition was crossed with susceptible cultivar Sharp 1 (Type 3) or cultivars Natsufushinari and F9-5-2 (Type 2) showing PMR at high temperature condition, a partial dominance was observed in the F1. On the other hand, the F1s of Natsufushinari or F9-5-2 crossed with Sharp 1 showed complete dominance for susceptibility.
Then it was considered that PI197088-5 is more useful for breeding material in resistance level and heredity than Natsufushinari or F9-5-2. The development of powdery mildew on leaf surface of the resistant host PI197088-1 which is sib-line of PI197088-5 was observed at different times after inoculation.
Conidia on leaf surface of PI197088-1 germinated within 12 hr after inoculation and first hyphae began to grow within 24 hr.
The retardation of hyphal growth and development was observed since two days after inoculation.
Conidia were hardly formed on epidermal of PI197088-1. The number of haustorium in epidermal of PI197088-1 was less than susceptible cultivar Sharp 1. Also fluorescing of epidermal cell was observed along the hyhae in PI197088-1 at about 6 days after inoculation.
This was considered to be a hypersensitive reaction.
These results would suggest that the PMR of PI197088-1 results from the inhibition of haustorium formation or of nutrition absorption through haustorium or hypersensitive reaction of epidermal cells.
When PI197088-5 (Type 1) showing PMR irrespective of temperature condition was crossed with susceptible cultivar Sharp 1 (Type 3) or cultivars Natsufushinari and F9-5-2 (Type 2) showing PMR at high temperature condition, a partial dominance was observed in the F1. On the other hand, the F1s of Natsufushinari or F9-5-2 crossed with Sharp 1 showed complete dominance for susceptibility.
Then it was considered that PI197088-5 is more useful for breeding material in resistance level and heredity than Natsufushinari or F9-5-2. The development of powdery mildew on leaf surface of the resistant host PI197088-1 which is sib-line of PI197088-5 was observed at different times after inoculation.
Conidia on leaf surface of PI197088-1 germinated within 12 hr after inoculation and first hyphae began to grow within 24 hr.
The retardation of hyphal growth and development was observed since two days after inoculation.
Conidia were hardly formed on epidermal of PI197088-1. The number of haustorium in epidermal of PI197088-1 was less than susceptible cultivar Sharp 1. Also fluorescing of epidermal cell was observed along the hyhae in PI197088-1 at about 6 days after inoculation.
This was considered to be a hypersensitive reaction.
These results would suggest that the PMR of PI197088-1 results from the inhibition of haustorium formation or of nutrition absorption through haustorium or hypersensitive reaction of epidermal cells.
Publication
Authors
M. Morishita, K. Sugiyama, T. Saito, Y. Sakata
Keywords
Cucumis sativus, Sphaerotheca fuliginea, Disease resistance, Hypersensitive reaction Inheritance
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