Production and identification of favorable characteristics of Brassica napus-Raphanus sativus moosomic adittion lines

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In this study, we tried to breed alloplasmic and autoplasmic Brassica napus-Raphanus sativus monosomic addition lines (MALs) mediated by the synthetic amphidiploid Raphanobrassica (RA89 and Rb63 lines), and also to survey favorable characteristics for B.napus breeding using them.In 2007, alloplasmic MAL with 8 types (a～i) except for the h-type and autoplasmic MAL with complete 9 types were produced using 175 RAPD markers specific to R-genome. In characteristics of the MALs, most of alloplasmic MAL having the radish cytoplasm showed male sterility and only the a-type produced normal flower and had a high pollen fertility (88%), suggesting to have fertility restoring gene(s) for male sterility in alloplasmic line.In 2008, we studied (1) identification and evaluation of clubroot resistance (CR) of radish chromosome, and (2) embryogenesis of MAL with d-chromosome of radish inducing low seed fertility. (1) Among the 9 types of MALs, only the c-type showed strong resistance (IC=73%, ID=0.7), … More on the other hand, other types showed complete susceptibility (IC=100%, ID=3.0). The result suggested that the major CR gene(s) may be located on the c-chromosome of the radish genome. (2) In 3 weeks after backcrossing of MALs × B.napus, embryos in all types except for the d-type were grown from torpedo (T) to mature (M) stage, on the other hand, one in d-type were globular (G) to heart (H) stage following to chlorosis. It was assumed that the low seed fertility in the d-type was induced by embryo underdevelopment.In 2009, for development of disomic addition lines (DALs), we studied ; (1) improvement of male transmission rate of radish chromosome in MALs by limited pollination, and (2) crossing with the same addition lines by both normal and limited pollination methods. (1) the 7 types except for the b- and c-types were advanced male transmission rate of alien chromosome by limited pollination (7.0～70.3%) in comparison with normal one (2.9～54.3%). (2) a large number of seed were successfully obtained with a range of 13.2 seeds per pod for the i-type (totally 787 seeds) to 1.7 for the g-type (132 seeds). From results of (1) and (2), it may be developed DALs in the near future. Less