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Asparagus (Asparagus officinalis L.) is a dioecious plant. In general, male and female plants are used for open-field culture and intensive cultivation, respectively. Farmers distinguish between the sexes by observing the form of the flower organs. However, because flowering begins 2-3 years after planting, the sexes cannot be differentiated at transplantation by using this method, and planting of an all-male population is not possible. In this study, the usefulness of loop-mediated isothermal amplification (LAMP), a simple method of gene amplification, for sex distinction at the DNA level was determined. In addition, the phenotypic differences in seeds and seedlings of male and female plants were investigated for application as a method of early sex distinction. By using the LAMP method, the sex could be correctly identified in 100% of the seedlings, suggesting that this method is effective for sex distinction at the gene level. Principal component analysis was conducted with 11 selected parameters after investigating the seeds and seedlings of both male and female plants. The results revealed that male plants tend to have many stalks or cladophylls and female plants tend to have large plant forms, suggesting that the sexes can be distinguished by the external appearance of the seedlings before planting. LAMP and observation of the seedling phenotypes could be useful methods of sex distinction for increasing the efficiency of asparagus breeding.

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The optimum conditions and mechanisms of inducing disease resistance by heat shock were investigated against gray mold (Botrytis cinerea) in cucumber (Cucumis sativus L.). The growth of inoculated mycelium was controlled most effectively by treatment at 40°C, for 2 minutes. Salicylic acid accumulated in the treated leaves under this condition and two peaks were obtained 24 and 96 hours after treatment. A pathogenesis-related protein, peroxidase gene (POX; M91372), was also expressed in the treated leaves and showed two peaks at 24 and 96 hours, respectively after treatment. Partial heat shock treatment was conducted by dipping only the first leaf of two leaves seedlings. Resistance and POX expression were induced not only in the treated leaves but also in the untreated second leaves. In conclusion, heat shock by means of hot water dipping could induce resistance against gray mold in cucumber. Systemic acquired resistance may have been obtained by some possible pathway.

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