Banca de DEFESA: GUSTAVO TORRES DOS SANTOS AMORIM
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : GUSTAVO TORRES DOS SANTOS AMORIM
DATA : 30/07/2019
HORA: 08:30
LOCAL: Sala 01
TÍTULO:
Preferential reproduction mode in vinca genotypes (Catharanthus roseus [L.] G. Don).
PALAVRAS-CHAVES:
Fluorescence microscopy, ISSR markers, medicinal plants, cleistogamy, plant breeding.
PÁGINAS: 91
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Melhoramento Vegetal
RESUMO:
The periwinkle (Catharanthus roseus [L.] G. Don) is distinguished because it is exclusive source of the alkaloids vincristina and vinblastina, nevertheless occur in very low concentrations in the species. Such alkaloids are used in chemotherapeutics for the treatment of tumors, leukemias and lymphomas. Therefore, it is fundamental to develop a breeding program in the search for superior genotypes for the production of vincristine and vinblastine. For this, it is necessary, initially, the study of the preferential reproduction mode of the species for the correct application of breeding methods. Considering the above, this research had the objective of studying the preferential reproduction mode in 10 genotypes of periwinkle from the germplasm collection of the Federal Rural University of Rio de Janeiro, based on the pollen:ovule (P:O), histochemistry pollen, emission and development of pollen tubes in vivo, pollen viability and stigma receptivity. As well as estimating the genetic diversity through ISSR markers among the analyzed genotypes. To estimate the pollen:ovule ratio, anthers of each flower were excised, and the pollen grains were counted under a microscope; ovaries from the same flowers were dissected, and the ovules were counted under stereomicroscope. The ratio (P:O) for each genotype was estimated according to Cruden. In the histochemical analysis of the pollen grains were used the dyes Sudan IV and the solution of I2KI for the detection of lipid and starch, respectively. The emission and development of pollen tubes in vivo were evaluated in flower buds (closed flowers) and flowers in the anthesis, under fluorescence microscopy, using 0.1% aniline blue fluorochrome. For the pollen viability, flower buds, were used the triple solution of Alexander and for the receptivity of the stigma was adopted the solution of alpha-naphthyl acetate, in closed flowers and in the anthesis. In the genotype analysis, 15 ISSR primers were used. The phenetic matrix was estimated by the dissimilarity index of Jaccard and the grouping of the genotypes was performed by UPGMA. The consistency of the clustering pattern was verified by cophenetic correlation. The results (P:O) indicated that eight of the 10 genotypes presented both facultative self-pollinated and facultative cross pollinated (mixed reproduction mode). However, two genotypes presented only one mode of reproduction, facultative cross pollinated, in UFRRJ VIN007, and facultative self-pollinated in UFRRJ VIN004. Receptive stigmas and high pollen viability in floral buds established favorable conditions for the occurrence of cleistogamy. Based on the emission and development of pollen tubes in vivo, it was verified that of the eight genotypes with mixed reproduction mode, six of them had a strong tendency to alogamy and all were autocompatible. It was also verified the occurrence of cleistogamy in 50% of the genotypes. In the case of UFRRJ VIN004 such occurrence was accentuated, which reinforces its tendency to autogamy. Thus, it was observed that seven genotypes, including UFRRJ VIN007, showed a strong tendency to alogamy. In view of this, a great diversity of reproductive strategies can be observed in periwinkle, since both self- pollinated and alogamy may be present. The high genetic diversity obtained through ISSR markers can be explained by the strong tendency of alogamy found in 70% of the analyzed genotypes.
MEMBROS DA BANCA:
Presidente - 1712769 - PEDRO CORREA DAMASCENO JUNIOR
Externo ao Programa - 2271445 - BRUNA RAFAELA DA SILVA MENEZES
Externo à Instituição - Diolina Moura Silva - UFES