xBrassicoraphanus, a new synthetic intergeneric hybrid between Brassica rapa L. ssp. pekinensis and Raphanus sativus L., also locally known as ‘Baemoochae’, is an interesting subject for studying polyploidy and genome plasticity in the family Brassicaceae, but very few genomic and cytogenetic information. Here, we analysed the chromosome complements and pairing of the most fertile lines, BB1 and BB5, using dual-color fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) to check their chromosomal segregation stability. The somatic chromosome complement of B. rapa was confirmed to be 2n=20 (2.8~4.8μm), of R.sativus, 2n=18 (2.0~3.3μm), and of xBrassicoraphanus, 2n=38 (2.2~5.0μm). There were eight, eight, and seventeen metacentric pairs and two, one, and two submetacentric pairs in B. rapa, R. sativus, and xBrassicoraphanus, respectively. Additionally, three, two, and five pairs of 5S rDNA and five, three, and eight pairs of 45S rDNA were observed in B. rapa, R. sativus, and xBrassicoraphanus, respectively. This suggests that both B. rapa (AA) and R. sativus (RR) genomes, particularly the rDNA arrays, co-exist in xBrassicoraphanus (AARR) genome. In meiosis I, nineteen bivalents were most frequent, and GISH analysis showed ten bivalents from the A genome. This study would provide a useful information for further genomic study of xBrassicoraphanus and its improvement as a new promising breeding variety.

The aim of this study was to select the abiotic tolerant sorghum mutants using chlorophyll a transient OJIP analysis of PSⅠ and PSⅡ so called Kautsky’s effect within 1 second. It was clearly identified that wwt-and drought tolerant sorghum mutants could be classified by wet factor index(WFI). On the basis of WFI, wet tolerant sorghum matants were classified as follows; Ⅰ group, MUT534 bmr/new, MUT525 bmr; Ⅱ group, M2P1207 bmr, 25M2-0404 bmr, MUT371 bmr24, unknown bmr22, 10M2-0775 bmr, MUT135 bmr23; Ⅲ group, M2P0411 bmr, MUT641 bmr, M2P1064 bmr36, MUT855 bmr, 25M2-0137 bmr/new, MUT436 bmr, M2P0929 bmr, 25M2-0026 bmr, 10M2-0387 bmr, 25M2-0173 bmr/new; Ⅳ group, 25M2-0698 bmr. In conclusion, for the selection of wet tolerance, four photochemical parameters such as Electron transport flux until PSI acceptors per PSII(RE1o/RC), Performance index for energy conservation from photons absorbed by PSII antenna, until the reduction of PSI acceptors(PI_total ABS), Driving force on absorption basis(DF_total ABS) and Electron transport flux from QA to QB per PSII(ETo/RC) were important photochemical parameters deduced from maximum quantum yield and electron transport efficiency.

Cytoplasmic male sterility (CMS) and fertility restoration have been utilized as valuable tools for F_1-hybrid seed production in many crops despite laborious breeding processes. Molecular markers for the selection of CMS-related genes help reduce the expenses and breeding times. A previously reported genomic region containing the Ppr-B gene, which is responsible for restoration of fertility and corresponds to the Rfo locus, was used to develop gene-based or so-called "functional" markers for allelic selection of the restorer-of-fertility gene (Rfo) in F_1-hybrid breeding of radish (Raphanus sativus L.) Polymorphic sequences among Rfo alleles of diverse breeding lines of radish were examined by sequencing the Ppr-B alleles. However, presence of Ppr-B homolog, designated as Ppr-D, interferes on specific PCR amplification of Ppr-B in certain breeding lines. The organization of Ppr-D, resolved by genome walking, revealed extended homology with Ppr-B even in the promoter region. Interestingly, PCR amplification of Ppr-D was repeatedly unsuccessful in certain breeding lines implying the lack of Ppr-D in these radishes. Ppr-B could only be successfully amplified for analysis through designing primers based on the sequences unique to Ppr-B that exclude interference from Ppr-D gene. Four variants of Rfo alleles were identified from 20 breeding lines. A combination of three molecular markers was developed in order to genotype the Rfo locus based on polymorphisms among four different variants. These markers will be useful in facilitating F_1-hybrid cultivar development in radish.