ISSN:
1432-2242
Keywords:
Brassica
;
Chimera
;
Segregation
;
Tissue culture
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The characteristics of intervarietal and interspecific chimeras synthesized by the graft-culture method were determined by morphology, anthocyanin pigmentation pattern, and crossing. In an intervarietal chimera between ‘YR-ranpou’ (green cabbage) and ‘Ruby ball’ (red cabbage) in Brassica oleracea, a segregation phenomenon was noted in which seeds giving rise to purple and green plants were both produced in a single capsule in F1 progeny from crosses of chimeras with YR ranpou, the anthocyanin-free graft partner type. The degrees of segregation varied, reflecting the structure of the chimeras. YR ranpou-dominant chimeras produced capsules in which seeds gave rise to green plants at a high frequency, while Ruby ball-dominant chimeras produced capsules in which seeds in one capsule gave rise to purple plants at a high frequency. Mixed chimeras produced capsules with green plants or purple plants more regularly than did other chimeral types. Furthermore, a chimeral type in which seeds gave rise to green and purple plants was found in 3.2% of the total crosses. Segregation patterns in the progenies corresponded with the chimeral types. Chlorophyll-deficient variation (resulting in variegation or the production of albino plants) was found at a frequency of 2.6%. These results show that chimeric tissues are actually in a mixed state and that either the ovary develops from more than two cells or else that variation occurs in the germ-cell layer. In interspecific chimeras between Ruby ball and Komatsuna (B. campestris) various types of chimeras generally showed low pollen fertility, few capsules, and low seed-setting. Progenies from selves (geitonogamy), open crosses and crosses with the two parental species produce a predominantly homogeneous genotype showing either the Ruby ball or the Komatsuna type. Only two crosses produced four interspecific hybrids which expressed variations in their morphological and isozymic characters.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00225149
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