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Application of chemical mutagenes in breeding of maize hybrid lines

By: Kapatadze, G | Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) | Tbilisi (Georgia) 14-17 Jun 2004.
Contributor(s): Bedoshvili, D [ed.] | Saaitashvili, I [coaut.].
Material type: materialTypeLabelBookAnalytics: Show analyticsPublisher: Tbilisi (Georgia) CIMMYT : 2004Description: p. 373.Subject(s): Breeding | Chemical composition | Crop yield | Georgia | Inbred lines | Maize | Mutagenicity | CIMMYT | Hybrids AGROVOCDDC classification: 633.1147 Summary: Maize holds the second leading place after wheat in grain crops cultivated in Georgia. Subsequently, maize breeding aims at development of high yield hybrids with different maturing periods. Mutagenesis, along with the methods of classic breeding practice, and namely, the chemical mutagenic agents have proved to be highly effective in developing of high yielding mutant lines with the high degree of heterosis. We have for the first time applied the well- known chemical mutagens, so called supermutagens (nitroethilurea, nitrozomethilurea ethylemene etc.) in breeding of maize in Georgia. The optimum doses of these mutagens were established: basically, 0,02% concentration proved to be the most effective one in the development of high mutation frequency and variance. Maize is quite f1exible genetica1ly and the self- pollinated lines of maize are highly responsive to treatment with chemical mutagens. Thus, the hybrid lines developed from the Georgian maize varieties are characterized by the high mutability due to their hybrid origin and the presence of mutagenic agents, creating wide opportunities for the development of mutant forms with the high spectrum of mutation frequency. Through the application of chemical mutagens tall, moderate-height and short-height lines of different vegetation periods were developed. The early, lodging-resistant short lines with the shortened vegetation period are useful for breeding of simple inbred-hybrid forms, while, at the same time, the tall and moderate-height remontant lines are the valuable germplasm for the development of simple inbred-hybrids of silage types. Maize has genetic predisposition of multi-ear formation. This is proved by the presence of numerous ear rudiments on its stems. However, blooming of female and male organs most frequently coincide with the availability of one, rarely two ears. Treatment with the chemical mutagens (in 0,02% rates) made possible induction of the genetic mechanism of productivity and development of 2 and 3-eared self-pollinated mutant lines, which were used as an initial breeding material for the development of highly productive simple inbred- hybrid forms. High yield of hybrids is conditioned by the genetic predisposition to "multi-eamess", inherited by hybrids from the parent lines. Ability of the formation of two ears is clearly marked in hybrids. Both ears on the plant are usually of the same size. Two-eared hybrids produce 30-35% more grains than the hybrids developed from the initial lines. Treatment with the chemical mutagens also enables development of multi-stemmed and multi-eared forms to be used for further breeding of silage hybrids. Thus, the chemical mutagenesis is an efficient tool for the development of high productive simple inbred-hybrids with the different maturity periods.Collection: CIMMYT Publications Collection
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Conference proceedings CIMMYT Knowledge Center: John Woolston Library

Lic. Jose Juan Caballero Flores

 

CIMMYT Publications Collection 633.1147 BED (Browse shelf) 1 Available 5I630072
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Abstract only

Maize holds the second leading place after wheat in grain crops cultivated in Georgia. Subsequently, maize breeding aims at development of high yield hybrids with different maturing periods. Mutagenesis, along with the methods of classic breeding practice, and namely, the chemical mutagenic agents have proved to be highly effective in developing of high yielding mutant lines with the high degree of heterosis. We have for the first time applied the well- known chemical mutagens, so called supermutagens (nitroethilurea, nitrozomethilurea ethylemene etc.) in breeding of maize in Georgia. The optimum doses of these mutagens were established: basically, 0,02% concentration proved to be the most effective one in the development of high mutation frequency and variance. Maize is quite f1exible genetica1ly and the self- pollinated lines of maize are highly responsive to treatment with chemical mutagens. Thus, the hybrid lines developed from the Georgian maize varieties are characterized by the high mutability due to their hybrid origin and the presence of mutagenic agents, creating wide opportunities for the development of mutant forms with the high spectrum of mutation frequency. Through the application of chemical mutagens tall, moderate-height and short-height lines of different vegetation periods were developed. The early, lodging-resistant short lines with the shortened vegetation period are useful for breeding of simple inbred-hybrid forms, while, at the same time, the tall and moderate-height remontant lines are the valuable germplasm for the development of simple inbred-hybrids of silage types. Maize has genetic predisposition of multi-ear formation. This is proved by the presence of numerous ear rudiments on its stems. However, blooming of female and male organs most frequently coincide with the availability of one, rarely two ears. Treatment with the chemical mutagens (in 0,02% rates) made possible induction of the genetic mechanism of productivity and development of 2 and 3-eared self-pollinated mutant lines, which were used as an initial breeding material for the development of highly productive simple inbred- hybrid forms. High yield of hybrids is conditioned by the genetic predisposition to "multi-eamess", inherited by hybrids from the parent lines. Ability of the formation of two ears is clearly marked in hybrids. Both ears on the plant are usually of the same size. Two-eared hybrids produce 30-35% more grains than the hybrids developed from the initial lines. Treatment with the chemical mutagens also enables development of multi-stemmed and multi-eared forms to be used for further breeding of silage hybrids. Thus, the chemical mutagenesis is an efficient tool for the development of high productive simple inbred-hybrids with the different maturity periods.

English

0409|AGRIS 0401|AL-Maize Program

Juan Carlos Mendieta

CIMMYT Publications Collection

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