Humulus japonicus (family Cannabaceae) ,known as wild hop, is a twining or prostrate vine that grows in wastelands, forest margins and thickets along streams in Korea. In July 2016, virus-like symptoms, including mosaic and yellow ring spots on leaves, were observed in H. japonicus in Eum-Sung, Korea. To identify a causal virus, four symptomatic leaf samples of H. japonicus plants were analyzed by transmission electron microscopy (TEM) in leaf dip-preparations. Tospovirus-like particles (about 80 to 100 nm in diameter) were observed from all the samples of H. japonicus plants. To confirm the TEM result, the symptomatic leaf samples were further analyzed using double-antibody sandwich (DAS)-ELISA kits (Agdia, Elkhart, U.S.A.) for the presence of potyviruses, cucumber mosaic virus, and tomato spotted wilt virus (TSWV). A positive control and a negative control (leaves of a healthy H. japonicus plant) were used. DAS-ELISA clearly showed that TSWV was only detected serologically from the naturally infected H....

The radish is a highly self-incompatible plant, and consequently it is difficult to produce homozygous lines. Bud pollination in cross-fertilization plants should be done by opening immature pollen and attaching pollen to mature flowers. It accordingly takes a lot of time and effort to develop lines with fixed alleles. In the current study, a haploid breeding method has been applied to obtain homozygous plants in a short period of time by doubling chromosomes through the induction of a plant body in the haploid cells, in order to shorten the time to breed inbred lines. We constructed genetic maps with an F1 population derived by crossing parents that show a superior and inferior ability to regenerate microspores, respectively. Genetic maps were constructed from the maternal and parental maps, separately, using the two-way pseudo-testcross model. The phenotype of the regeneration rate was examined by microspore cultures and a quantitative trait loci (QTL) analysis was performed based on the regeneration rate. From the results of the culture of microspores in the F1 population, more than half of the group did not regenerate, and only a few showed a high regeneration rate. A total of five significant QTLs were detected in the F1 population, and five candidate genes were found based on the results. These candidate genes are divided into two classes, and appear to be related to either PRC2 subunits or auxin synthesis.

Suhyoung Park*, Suk-Woo Jang, and Seung-Kook Choi. Korean J. Breed. Sci. 2020;52:41-52. https://doi.org/10.9787/KJBS.2020.52.1.41

Min Young Park, Ha-Young Jang, Yong Pyo Lim, Jung-Soo Lee, and Suhyoung Park. J Plant Biotechnol 2017;44:27-34. https://doi.org/10.5010/JPB.2017.44.1.027