Italian ryegrass Mutation breeding has been mainly established in seed propagated, self-pollinated species. Although several methods have been widely used for the screening of mutants in self-pollinated species by the single-seed descent approach [18,19] and by single seed descent (one-plant-onegrain method, Yoshida [20]), these methods have not been applied to cross-pollinated species. Ukai [21] developed a new method for obtaining mutants of cross-pollinated species efficiently in a temperate forage grass, Italian ryegrass ( Lolium multiflorum L.). The method was called the “Crossing-within-Spike-Progenies Method.” This method is composed of 1) taking seeds separately from each spike from a population of plants irradiated with Gamma-rays, 2) sowing the seeds in a hill plot as a spike-progeny, 3) isolating each hill from others at the time of flowering and allowing the open-pollination of plants within hills, and 4) taking seeds from each of the hills and sowing the seeds in hill progenies for the screening of mutants. This procedure is repeated each year. When 300Gy of Gamma-ray was irradiated to the seed, the frequency of chlorophyll mutations was approximately 70.6% per hill progeny and 1.87% per plant. In contrast, open-pollinated populations exhibited that only 10% per progeny and 0.12% per plant, respectively. This method will be applied to the other wind- or insect-pollinating outcrossing crop species.
Italian ryegrass Mutation breeding has been mainly established in seed propagated, self-pollinated species. Although several methods have been widely used for the screening of mutants in self-pollinated species by the single-seed descent approach [18,19] and by single seed descent (one-plant-onegrain method, Yoshida [20]), these methods have not been applied to cross-pollinated species. Ukai [21] developed a new method for obtaining mutants of cross-pollinated species efficiently in a temperate forage grass, Italian ryegrass ( Lolium multiflorum L.). The method was called the “Crossing-within-Spike-Progenies Method.” This method is composed of 1) taking seeds separately from each spike from a population of plants irradiated with Gamma-rays, 2) sowing the seeds in a hill plot as a spike-progeny, 3) isolating each hill from others at the time of flowering and allowing the open-pollination of plants within hills, and 4) taking seeds from each of the hills and sowing the seeds in hill progenies for the screening of mutants. This procedure is repeated each year. When 300Gy of Gamma-ray was irradiated to the seed, the frequency of chlorophyll mutations was approximately 70.6% per hill progeny and 1.87% per plant. In contrast, open-pollinated populations exhibited that only 10% per progeny and 0.12% per plant, respectively. This method will be applied to the other wind- or insect-pollinating outcrossing crop species.
การแปล กรุณารอสักครู่..
