Data/hora: 03/06/2024 15:32:20

Biblioteca(s): | Embrapa Cerrados.
Data corrente: | 04/11/1998
Data da última atualização: | 04/11/1998
Autoria: | SANTOS, J. P.
Título: | A brasilian corn germplasm collection screened for resistence to Sitophilus zeamais Motschulsky (Coleoptera: curculionidae) and Sitotroga cerealella (Olivier) (Lepidoptera: gelechiidae).
Ano de publicação: | 1977
Fonte/Imprenta: | West Lafayette: Purdue University, 1997.
Páginas: | 182p.
Idioma: | Inglês
Notas: | MSc. Thesis.
Conteúdo: | Various insects attack every part of the corn plant throughout its growth, starting with the seeds as it germinates, and continuing through the roots, stalk, leaves and mature ears. After harvest, infested corn grain, if improperly stored continues to be damaged. Several species begin their destructive feeding even before the grain is harvested. Of these, the maize weevil, Sitophilus zeamais Motschulsky, the rice weevil, Sitophilus oryzae L., both coleoptera, curcullonidae and the Angoumois grain moth, Sitotroga cerealella (Olivier), lepidoptera, gelechiidae, cause especially heavy damage in southern United States and in similar climates abroad. Host plant resistance is the ideal method of controlling insects and at the same time preventing enviromental pollution (Gallun 1972), and as noted by bigger (1941), the corn plant undoubtedly developed a substantial degree of resistance to many insect pests during the hundreds of years of its cultivation. Thus, it is very probable that it may have resistance to some of the stored-grain pests which are a serious threat, especially in tropical climates where farmers depend on the sun to dry the corn in the field. This practice allows the stored grain insect a longer period to infest the corn. The objectives of the present sdudy were (1) to make a thorough review of the literature for the maize weevil and the angoumois grain moth, and (2) to identify possible resistance to these stored grain pests. It was anticipated that the genetic variation among populations of corn are diverse enough to make it possible, initially, to select among populations, and then to select within populations for resistance quently, commercial hybrids produced. The first objective proposed for this study was met by reviewing about 500 publications, including books and scientific papers, from United States and foreign countries. These publications related only to studies on biology, behavior, and host moth plant resistance to maize weevil, rice weevil and angoumois grain moth. About 300 papers were selected and cited in the list of references. The second objective was met by using a "free-choice" experimental design which provided for the screening tests data and one-way analysis of variance and Duncan's multiple  Range test to separate the experimental corn into groups of (a) highly preferred entries (12, 18, 21, 24, 25 and 35); (b) nonpreferred entries (2, 5, 6, 10, 14, 27, 19 and 34), evaluated by the number of adults trapped, number of eggs laid, number of offspring produced, mortality, and damage done in samples of each corn population. Data from a "nochoice" design supported those from the "free-choice" and provided information such that those entries considered as highly preferred in the "free-choice" test were also those which had more eggs, provided more offspring, had higher mortality and were more heavily damaged than the nonpreferred entries. Entry numbers 1, 6, 27 and 34 were resistant to both maize weevil and angoumois grain moth, constituting potential parents for a breeding program. Entry numbers 18 and 21 were susceptibles to both insect pests. Evidences that genetic variations within corn populations exist were found when samples (50 grains) of corn population were subjected to infestation of 20 maize weevils and their progeny had some untouched kernels at the end of 84 days (Fig. 28). These evidences, further show that selection within populations is possible. Based on these findings, it is evident that this is a promising line of research.
Palavras-Chave: | Germplams; Maize; Resistencia a praga; Stored products pests; Traca dos cereiais.
Thesagro: | Armazenamento; Germoplasma; Gorgulho dos Cereais; Lagarta; Melhoramento Genético Vegetal; Milho; Praga de Produto Armazenado; Sitophilus Zeamais; Sitotroga Cerealella; Variedade Resistente; Zea Mays.
Thesaurus Nal: | pest resistance; plant breeding; storage.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)
Exemplares: | CPAC - (19434-1) - ADD - TS - -- - T001/77 - SAN - T001/77 - DIS