Results of the study of the productive tillering heredity durum wheat crosses
Naskidashvili, M.P.
Results of the study of the productive tillering heredity durum wheat crosses - Tbilisi (Georgia) CIMMYT : 2004 - p. 281-282 - Printed
Abstract only
Genetic research on of productive tillering is quite scarce, and consequently thre is insufficient data on the nature of heredity of this trait. Some statistics on the impact of productive tillering on yield is available. Some researchers believe that intensive tillering has negative effect on yield. Other researchers consider productive tillering to be an important component of crop forming, believing that 53-64% of yield depends on productive tillering. Opinions differ also with regard to the heredity of productive tillering in the first hybrid generation. Some researchers believe that the heredity of productive ti1lering is of over dominance nature, other researchers sllnnose that this trnit is inherited through the intermediate inheritance, some studies suggest the phenomenon of depression. In the given experiment productive tillering in hybrids of the first generation was inherited by over dominance in 76% of combinations, wherein the authentic heterosis varied within +2.5% and +25%. In 10% of hybrids it matches the best parent and in 13% depression is observed. Rendering the results of the experiment in absolute figures the high heterosis capacity of hybrids becomes obvious. Georgian parental form had 2.9 of productive tillers, whereas foreign parental forms had 2.2-4.6 productive tillers. The same characteristic in hybrids varied within 2.1-5.2. At the same time no difference between direct and inverse combinations was observed. Combinations Rolettex x Cerulescens19/28 and Cocorit 71 x Cerulescens 19/28 have expressed high heterosis. These combinations developed from 3.9 to 5.2 productive tillers per plant. Similarly the degree of heterosis was high (hp=2.3-1 0.0). The genotypes of foreign origin used in crosses, such as Rolette (USA) and Cocorit (Mexico) had high productive tillering ranging within 3.8-4.6 productive tillers per plan, whereas in the first generation of their hybrids number of productive tillers varied within 4.0-5.2. Therefore, these varieties can be used as donors of high productivity tillering. Productive tillering in 63.3% of hybrid combinations of the second generation has significantly exceeded that ofthe parental forms. Similarly to the first generation high level of productive tillering was observed the second generation population produced by crossing of Georgian hybrid variety Cerulescens 19/28 by foreign varieties Rolette and Cocorit 71. In the second generation produced from these varieties individual plants with the number of productive tillers varying within 5.0- 7.0 were segregated from the combinations of direct and inverse crosses. Thus, the experiments ascertained overdominant nature of productive tillering in the first hybrid generation, while the intermediate heredity and depression were also observed. Productive tillering in the majority of the second generation hybrid combinations is transgressive and, consequently, offers an opportunity to select types with high productive tillering, facilitating production highly adapted input- respousive durum wheat varieties in Georgia. The most interesting aspect of the results of our experiments from the viewpoint of breeding practice is the fact that the individual plants segregated from the hybrids of genetically diverse forms offer diverse productive tillering features enabling forthe establishment of the completely new germplasm.
English
Crop yield
Crossbreeding
Heritability
Heterosis
Varieties
Wheat
Genetic resources
Hybrids
CIMMYT
633.1147 / BED
Results of the study of the productive tillering heredity durum wheat crosses - Tbilisi (Georgia) CIMMYT : 2004 - p. 281-282 - Printed
Abstract only
Genetic research on of productive tillering is quite scarce, and consequently thre is insufficient data on the nature of heredity of this trait. Some statistics on the impact of productive tillering on yield is available. Some researchers believe that intensive tillering has negative effect on yield. Other researchers consider productive tillering to be an important component of crop forming, believing that 53-64% of yield depends on productive tillering. Opinions differ also with regard to the heredity of productive tillering in the first hybrid generation. Some researchers believe that the heredity of productive ti1lering is of over dominance nature, other researchers sllnnose that this trnit is inherited through the intermediate inheritance, some studies suggest the phenomenon of depression. In the given experiment productive tillering in hybrids of the first generation was inherited by over dominance in 76% of combinations, wherein the authentic heterosis varied within +2.5% and +25%. In 10% of hybrids it matches the best parent and in 13% depression is observed. Rendering the results of the experiment in absolute figures the high heterosis capacity of hybrids becomes obvious. Georgian parental form had 2.9 of productive tillers, whereas foreign parental forms had 2.2-4.6 productive tillers. The same characteristic in hybrids varied within 2.1-5.2. At the same time no difference between direct and inverse combinations was observed. Combinations Rolettex x Cerulescens19/28 and Cocorit 71 x Cerulescens 19/28 have expressed high heterosis. These combinations developed from 3.9 to 5.2 productive tillers per plant. Similarly the degree of heterosis was high (hp=2.3-1 0.0). The genotypes of foreign origin used in crosses, such as Rolette (USA) and Cocorit (Mexico) had high productive tillering ranging within 3.8-4.6 productive tillers per plan, whereas in the first generation of their hybrids number of productive tillers varied within 4.0-5.2. Therefore, these varieties can be used as donors of high productivity tillering. Productive tillering in 63.3% of hybrid combinations of the second generation has significantly exceeded that ofthe parental forms. Similarly to the first generation high level of productive tillering was observed the second generation population produced by crossing of Georgian hybrid variety Cerulescens 19/28 by foreign varieties Rolette and Cocorit 71. In the second generation produced from these varieties individual plants with the number of productive tillers varying within 5.0- 7.0 were segregated from the combinations of direct and inverse crosses. Thus, the experiments ascertained overdominant nature of productive tillering in the first hybrid generation, while the intermediate heredity and depression were also observed. Productive tillering in the majority of the second generation hybrid combinations is transgressive and, consequently, offers an opportunity to select types with high productive tillering, facilitating production highly adapted input- respousive durum wheat varieties in Georgia. The most interesting aspect of the results of our experiments from the viewpoint of breeding practice is the fact that the individual plants segregated from the hybrids of genetically diverse forms offer diverse productive tillering features enabling forthe establishment of the completely new germplasm.
English
Crop yield
Crossbreeding
Heritability
Heterosis
Varieties
Wheat
Genetic resources
Hybrids
CIMMYT
633.1147 / BED