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An efficient chimera formation method by tissue culture combined with grafting was studied in Brassica. Cabbage cultivars "Ruby-ball" and "YR-ranpou" (Brassica oleracea) were used for intervarietal chimera formation. Seven-day-old seedlings leaving one of two cotyledons were approach-grafted and cultured in vitro (AGSC method). Chimeric shoots were obtained by the subculture of directly growing chimeric leaves (DGCL) from grafted part and cross-cut section of the united part after the graft culture. These were rooted and grown to complete chimera. An approach-grafted culture method was also available for interspecific chimera formation between "Komatsuna" (B. campestris) and "Ruby-ball" (B. oleracea), resulting in 20% formation per culture. Interspecific chimeras were identified as complex and peripheral-sectorial type by microscopic observation and the electrophoretic analysis of acid phosphatase isozyme pattern. The AGSC method was more effective than the usual Winkler's graft method and a simple mixed culture of heterogeneous cells or tissues.

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The genetic nature of low capsaicin content in variant strains induced by grafting was elucidated by crossing the G 5 S23 strain with the two cultivars, 'Yatsubusa' (Capsicum annuum L. var . fasciculatum Ilish) andSpanish Paprika' (C. annuum L. grossum Sendt) originally used for grafting . Decreased capsaicin synthesis was a stable characteristic for at least several generations from G 5S 16 to G5S 23 and was transmitted to the progenies of crosses . This fact shows that the decreased capsaicin synthesis is a genetic trait in the graft-induced variant strains . The genetically dependent characteristic of pungency of the G 5 S23 , ' Yatsubusa'and `Spanish Paprika' were analysed by High Perfomance Liquid Chromatography measurement and tasting assay .Cross experiment between the G5 S 23 strain, hot parent 'Yatsubusa' and sweet parent `Spanish Paprika' showed that `pungent' and `sweet' for pungency chracteristics are generally controlled by at least two pairs of genes . Although segregation of capsaicin content and pungency was clearly demonstrated in F 2 progenies from reciprocal crosses between the G 5 S23 strain and `Spanish Paprika', F 2 progenies from reciprocal crosses between G5 S 23 and 'Yatsubusa' were all hot and did not develop low capsaicin plants .

Genetic changes induced by grafting were observed in soybean storage proteins, involving the 11s acidic subunit composition and Kunitz trygsin inhibitor. Changes from GlylGlyl to Glylgly, involved the 11s acidic subunit, and those from Tr'Tr to n3T? Involved the KTI in the first progeny (GtSt) in the scion (Gly,Gly,T?T?, var. Kinzu) grafted onto var. Raiden (glylglyl Ti3Ti3). The progenies GtSz and G$t from the seeds that had been changed segregated for both proteins. However, the segregation ratio in the progenies were different from those of the Fz's from the sexual crosses between Kinzu and Raiden used for grafting. These findings show that the changes (changed genes) were transmitted to the progenies in an unstable manner.