ISSN:
1573-5044
Keywords:
Medicago sativa
;
direct embryogenesis
;
genotypic variation
;
mesophyll protoplast
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Clones of three cultivars of Medicago sativa (‘Rambler’, ‘Regen S’ and ‘Rangelander’) were used as sources of mesophyll protoplasts. Although all three clones readily produced protoplasts, the subsequent development patterns in culture varied greatly among genotypes, with protoplasts from ‘Regen S’ and ‘Rambler’ forming calli which could be induced to form embryos, and protoplasts from ‘Rangelander’ undergoing direct embryogenesis. Protoplasts of ‘Regen S’ exhibited high rates of division while those of ‘Rangelander’ tended to aggregate with only a few cells per aggregate surviving. The surviving cells gave rise to proembryos within the aggregates; these proembryos developed into differentiated embryos after 5–7 weeks of culture. Based on the initial protoplast population, the efficiency of embryo formation averaged 0.13% and ranged from 0.001–0.4%. Observations during the early stages of culture indicated that cell aggregation was a prerequisite for direct embryogenesis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00044247
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