No description available.

Thesis--Bonn, 1973. / Vita. Includes bibliographical references (p. 409-439).

Thesis (M.A.)--University of Wisconsin--Madison, 1993. / Typescript. Title from title screen (viewed Mar. 15, 2007). Includes bibliographical references (leaves 51-52). Online version of the print original.

Hybridization within Sorghum bicolor (L.) Moench has been the primary means of creating genetic diversity needed for sorghum crop improvement. While significant variation exists within S. bicolor, there are several traits that can be improved and potential opportunities to improve S. bicolor if secondary and tertiary germplasm pools could be accessed. Recently, the discovery of the iap (Inhibition of Alien Pollen) mutant and its introgression into more breeding-amenable genetic background has facilitated the development of S. bicolor germplasm with genetic diversity not previously seen within Sorghum. The key to producing this variation is the homozygous recessive mutant gene iap which removes an important reproductive isolation barrier to hybridization. Development of a S. bicolor accession (Tx3361) containing the mutant allele iap and ms3 has allowed introgression of genomic regions from divergent sorghum species into S. bicolor. Given the success with divergent sorghum species, there is a real interest in assessing the potential of this mutant to facilitate intergeneric hybridization. The objective of this study was to determine the range and effectiveness of the iap mutant to allow pollen tubes of Poaceae species outside of the genus Sorghum to grow into S. bicolor pistils. Accessions from the genera Zea, Miscanthus, Pennisetum, and Sorghastrum were used as pollen donors onto Tx3361 and fluorescent microscopy was used to determine the distance through the pistils that foreign pollen tubes grew. Results indicate high levels of pollen tube growth into the ovaries of S. bicolor pistils for two accessions of Pennisetum ciliare (L.) Link and four accessions of Zea mays L. Pollen tubes of other accessions tested did grow to the ovary but in very small numbers. While the recovery of embryos was not attempted in this study, the results indicate that there is potential for hybridization, but the specific pollinator within a species is critical in this attempt.

Thesis (Ph. D.)--Uppsala, 1933. / Includes bibliographical references (p. [vii]-x).

Thesis (M.A.)--University of Wisconsin--Madison, 1993. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 51-52).

Thesis (M.A.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 172-180). Also available on the Internet.

Thesis (M.A.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 172-180). Also available on the Internet.

Thesis (M. A.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 206-218.

Made available in DSpace on 2014-06-11T19:30:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2003Bitstream added on 2014-06-13T20:00:36Z : No. of bitstreams: 1 lima_mwp_dr_botfca.pdf: 347050 bytes, checksum: 56204ce7428a20502b79ab1119ebfc3f (MD5) / Com a crescente demanda de milho doce no mercado brasileiro para diversas finalidades, torna-se necessário o desenvolvimento de materiais cada vez mais produtivos. Neste contexto, esse trabalho objetivou avaliar as capacidades geral e específica de combinação de linhagens endogâmicas de milho doce, portadoras do gene SHRUNKEN-2, bem como, identificar híbridos simples promissores para utilização como enlatados e/ou comercialização de espigas na forma de milho verde. Para isso, foram obtidos híbridos simples por meio de cruzamentos dialélicos parciais incompletos. As avaliações deram-se no ano agrícola 2000/2001 em São Manuel-SP, Piracanjuba-GO e Bragança Paulista-SP. Foram conduzidos 4 experimentos por local, utilizando o delineamento em blocos casualizados no esquema de látice simples 10 x 10, onde as parcelas constituíram-se de 1 linha de 5 metros. A partir dos dados de produção total de espigas com palha, produção comercial com palha, produção comercial sem palha, alturas de planta e de espiga e índice de espigas dos híbridos, foram obtidas as estimativas dos parâmetros genéticos, utilizando-se o método dos quadrados mínimos. Após o desdobramento do quadrado médio dos tratamentos em capacidades geral do grupo 1, do grupo 2 e da capacidade específica de combinação, constatou-se maior variabilidade por parte da capacidade geral de combinação do grupo 2 de genitores; o efeito gênico predominante foi o de origem não aditiva; ocorrência de genitores com boa capacidade combinatória; existência de híbridos promissores para cada local de avaliação. / With the crescent demand of swet corn in the Brazilian market for distinct purposes, it becomes necessary the development of materials more and more productives. In this context, this research objected to evaluate the general and specific combining abilities of sweet corn inbred lines with SHRUNKEN – 2 gene, as well as identify single-crosses promissing to utilization like canned and/ or commercialization of ears as green corn. For that, it was obtained single-crosses by using of partial diallel incomplete crosses. The evaluations were done in 2000 / 2001 in São Manuel – SP, Piracanjuba – GO e Bragança Paulista – SP, Brazil. It was carried out four experiments per place by utilizing the 10 x 10 simple lattice design, where the plots consisted in one line of five meters. From the basis of total production of ear with husk, commercial production with husk, commercial production without husk, plant heigh and ear, and the index of ear from single cross, was obtained by estimation of minimum square. Afterwards the unrolled of the mean square of the treatments in general combining ability of group 1 and group 2, and of the specific combining ability evidencied a large variability apart of general combining ability of the group 2 parentals; the predominant gene ffect was non- additive; occurence of parentals with a good combining ability; and the existence of promissing single crosses for each evaluated place.