Data/hora: 29/05/2024 19:12:31

Biblioteca(s): 	Embrapa Soja.	
Data corrente: 	06/04/2004	
Data da última atualização: 	27/07/2007	
Autoria: 	PAGLIARINI, M. S.; BIONE, N. C. P.; ALMEIDA, L. A. de.	
Título: 	Degeneration of the generative cell in soybean [Glycine max (L.) Merrill] as the cause of male steriity.	
Ano de publicação: 	2004	
Fonte/Imprenta: 	In: WORLD SOYBEAN RESEARCH CONFERENCE, 7.; INTERNATIONAL SOYBEAN PROCESSING AND UTILIZATION CONFERENCE, 4.; CONGRESSO BRASILEIRO DE SOJA, 3., 2004, Foz do Iguassu. Abstracts of contributed papers and posters. Londrina: Embrapa Soybean, 2004.	
Páginas: 	p. 240.	
Série: 	(Embrapa Soja. Documentos, 228). 
	
Idioma: 	Inglês	
Notas: 	Editado por Flávio Moscardi, Clara Beatriz Hoffmann-Campo, Odilon Ferreira Saraiva, Paulo Roberto Galerani, Francisco Carlos Krzyzanowski, Mercedes Concordia Carrão-Panizzi.	
Conteúdo: 	Male sterility in plants impairs the male gametophyte function and leaves intact the potential for female reproduction. Mutants affecting male sterility have potential applications in breeding methodology studies and for commercialization of hybrids. The presence of genes acting after meiosis and affecting the post-meiotic microspore development has never been reported in soybean. For the first time, the cytological details are provided in a spontaneous male-sterile mutation affecting the male gametophyte development, specifically the generative cell. Mutation has been detected in line BR97-17739, selected in the breeding program developed by Embrapa - National Soybean Research Center. Meiotic division and male gametophyte development were analyzed in ten male-sterile, female-fertile plants. Sterile plants were identified, flower buds were collected in ideal stage for meiotic analysis and fixed in a mixture of ethanol 95%, chloroform and propionic acid (6:3:2 v/v) for 24 h. They were then transferred to 70% alcohol and stored at 40C until use. Microsporocytes were prepared by squashing and stained with 1% propionic carmine. Despite the high frequency of normal microspores, pollen sterility was total. After callose dissolution, microspores were released into the anther loculle and interphase nucleus was displaced from the center to one side of the cell. Displacement continued throughout normal microspore mitosis (PMI). After telophase, the hemispherical phragmoplast marked the place of cytokinesis. Typical generative cell, adjacent to the plasma membrane, and the vegetative one, containing most of the cytoplasm, were formed. In spite of the well-formed generative cell, pollen mitosis (PMII) failed to occur. The generative cell degenerated and was completely destroyed. The 3:1 segregation ratio for male sterility in this line and its progenies indicate that a single recessive gene controls mutation. Similar gametophytic mutation has never been reported in higher plants. For double fertilization in angiosperms, two sperm cells are produced in the male gametophyte after two mitotic cell divisions in the haploid phase. Posterior to meiosis, the microspore divides into a larger vegetative cell and a smaller generative one during microspore mitosis (PMI). Then the generative cell undergoes another mitotic cell division, pollen mitosis (PMII), to produce two sperm cells. During double fertilization, one sperm cell fuses with the egg cell to form the embryo and the other fuses with the central cell to form the endosperm. Male-sterile mutation provides source material for studies in plant breeding, genetics, reproductive biology and molecular biology. The available systems of male sterility in soybean have proved useful in soybean genetics and breeding. 	
Categoria do assunto: 	--	
Registro original: 	Embrapa Soja (CNPSO)	
Exemplares: 	CNPSO - (23749-1) - UMT - PL - -- - RF 633.34072 - W927a -  - DIS