Meiose e viabilidade do pÃlen em Solanum commersonii ssp. e Solanum tuberosum L. / Meiosis and pollen viability in Solanum commersonii ssp. and Solanum tuberosusm L.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

One of the main difficulties to promote genes introgression from wild species to the cultivated species consists in the ploidy barriers, endosperm balance number (EBN) and meiotic abnormalities. In this work the evaluations consisted of pollen viability, meiosis and frequency of non-reduced pollens, with the objective to indicate promising materials, which may be used in breeding programs. Three Solanum commersonii commersonii (SCC) clones and two Solanum commersonii malmeanum (SCM) were evaluated, together with six other clones, 4 different cultivars and a hybrid of Solanum tuberosum, in the studies of pollen viability by the techniques of in vitro germination and staining. Diameters of S. commersonii ssp pollens were measured to estimate the frequency of non-reduced pollens. For meiosis evaluation, the squashing technique was used in the clones S. commersonii ssp., as well as to the Chiquita cultivar of S. tuberosum. The techniques of enzymatic maceration and airdrying, for meiosis studies, were used to verify chromosome paring in the S. commersonii ssp clones. In general, the wild clones presented higher amounts of viable pollens, in relation to other cultivated species. The SCC 07 clone outstands from the other S commersonii ssp clones for presenting a high percentage of pollen germination associated to the occurrence of non-reduced pollen, besides presenting low frequencies of meiotic abnormalities. Thus, it can be considered a promising material to be used for breeding. Although the SCC 100 clone has presented a high frequency of non-reduced pollen, it showed low pollen viability, due to a high percentage of meiotic abnormalities. Although the SCM 57 and SCM 60 clones, have not presented non-reduced pollens, they have meiotic mechanisms which possibly can conduct to the formation of nonreduced pollen, and also the S. commersonii ssp clones with the highest rates of pollen viability. The Chiquita cultivar presented good pollen viability and a low percentage of meiotic abnormalities, confirming its good behavior as male parent in the UFLA breeding program. In the chromosome paring studies, the SCC 07 clone presented regular pairing showing twelve bivalents in all cells evaluated.

ASSUNTO(S)

citologia vegetal meiose pollen melhoramento genÃtico vegetal pÃlen batata potato plant breeding meiosis

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