[Show abstract][Hide abstract] ABSTRACT: A population of F7 recombinant inbred lines (RILs) was made from a cross between susceptible ('Santou') and resistant (PI197088-1) lines of cucumber in order to study powdery mildew resistance loci. Susceptibility to powdery mildew in the F7 RIL individuals showed a continuous distribution from susceptible to resistant, suggesting that powdery mildew resistance is controlled by quantitative trait loci (QTLs). A QTL analysis identified two and three loci for powdery mildew resistance under 26 and 20 degrees C conditions, respectively. One QTL was found in the same position under both temperature conditions. Therefore, it is more likely that one major QTL acts under both temperature conditions and that other QTLs are specific to the two temperature conditions. The above results suggest that the four QTLs are controlled in a different temperature manner, and that their combination played an important role in expressing a high level of resistance to powdery mildew in this cucumber population. Sequence-tagged site (STS) markers associated with each QTL were developed and would be useful for breeding a cucumber line with a high level of powdery mildew resistance.
Preview · Article · Feb 2006 · Theoretical and Applied Genetics
[Show abstract][Hide abstract] ABSTRACT: For the mass production of seedless watermelons induced by pollination of soft-X-irradiated pollen, it is necessary to prepare a lot of irradiated male flowers or pollen prior to pollination. We investigated the storage methods of male flowers and pollen. The characteristics of seedless watermelon induced by the stored pollen were also investigated. When the male flowers were stored with silica gel (ca. 10 times in weight) in sealed container and kept at 5, the pollen germination on artificial medium was retained well until 20 days after storage. For the long time storage (beyond 1 month), the use of ethyl acetate (dehydrated) as organic solvent and -20 condition was suitable. There were no differences in quality between the seedless fruits induced by fresh pollen and long time stored pollen.
No preview · Article · Oct 2002 · Acta horticulturae