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Breeding for resistance to the maize weevil (Stophilus zeamaiz Motsch.): is it feasible?

By: Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) Kenya | Dhliwayo, T.
Contributor(s): Friesen, D.K.|Palmer, A.F.E | Pixley, K.V [coaut.].
Material type: materialTypeLabelBookAnalytics: Show analyticsPublisher: Nairobi (Kenya) KARI|CIMMYT : 2002Description: p. 134-138.ISBN: 970-648-120-6.Subject(s): Inheritance (genetics) | Insecticides | Maize | Pest control | Protein content | Sitophilus zeamais | Storage | Technology | Tropical zones | CIMMYT | KARI | Genetics AGROVOCSummary: Maize weevil (Sitophilus zeamais Motschulsky) is an important pest of maize in the tropics, particularly where grain is stored on-farm and without chemical protectants. This study was to determine if improvement of weevil resistance of maize is possible through conventional breeding techniques. Selection for weevil resistance was done at CIMMYT-Zimbabwe for two genetically broad-based and four bi-parental maize populations. One hundred or more S1 cobs were selected from each of the populations, they were individually shelled and grain was evaluated for weevil resistance in unreplicated tests at 28:2°C and 70:5% relative humidity in a laboratory at Harare. The number of weevils emerged (F1 progeny) after six weeks of incubation was used as the primary selection criterion. The most resistant 10% and most susceptible 10% of the lines for each population were selected and intercrossed to form two synthetics per population. In addition, all S1 lines from the two genetically broad-based populations were advanced to S2, and three representative S2 cobs were used to evaluate weevil resistance for each family, with grain from each S2 cob constituting a replicate. Divergent selections were then made based on the resistance of the S2 families (replicated) and the S2 individual lines (unreplicated) to form four synthetics per population. Selection using replicated S2 samples was successful for both populations where it was applied, and resulted in 16%, 49° and 20% (all statistically significant) difference between divergently selected synthetics for progeny emerged, weight loss and Dobie index, respectively. SI unreplicated selection was successful for two of the six populations where it was applied, while S2 unreplicated selection was never successful. Our results confirmed that it is possible to improve maize populations for resistance to maize weevil.Collection: CIMMYT Staff Publications Collection
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Conference proceedings CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Staff Publications Collection CIS-4171 (Browse shelf) 1 Available 630212
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Maize weevil (Sitophilus zeamais Motschulsky) is an important pest of maize in the tropics, particularly where grain is stored on-farm and without chemical protectants. This study was to determine if improvement of weevil resistance of maize is possible through conventional breeding techniques. Selection for weevil resistance was done at CIMMYT-Zimbabwe for two genetically broad-based and four bi-parental maize populations. One hundred or more S1 cobs were selected from each of the populations, they were individually shelled and grain was evaluated for weevil resistance in unreplicated tests at 28:2°C and 70:5% relative humidity in a laboratory at Harare. The number of weevils emerged (F1 progeny) after six weeks of incubation was used as the primary selection criterion. The most resistant 10% and most susceptible 10% of the lines for each population were selected and intercrossed to form two synthetics per population. In addition, all S1 lines from the two genetically broad-based populations were advanced to S2, and three representative S2 cobs were used to evaluate weevil resistance for each family, with grain from each S2 cob constituting a replicate. Divergent selections were then made based on the resistance of the S2 families (replicated) and the S2 individual lines (unreplicated) to form four synthetics per population. Selection using replicated S2 samples was successful for both populations where it was applied, and resulted in 16%, 49° and 20% (all statistically significant) difference between divergently selected synthetics for progeny emerged, weight loss and Dobie index, respectively. SI unreplicated selection was successful for two of the six populations where it was applied, while S2 unreplicated selection was never successful. Our results confirmed that it is possible to improve maize populations for resistance to maize weevil.

Genetic Resources Program|Global Maize Program

English

0409|AGRIS 0401|AL-Maize Program

Juan Carlos Mendieta

INT3355|INT1617

CIMMYT Staff Publications Collection

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