The presence of grassland biomes and species cannot be predicted by examining bottom up causes such as precipitation and temperature. Top down causes including herbivory and fire seem to be major controlling aspects w...The presence of grassland biomes and species cannot be predicted by examining bottom up causes such as precipitation and temperature. Top down causes including herbivory and fire seem to be major controlling aspects with other factors secondary. We examined soil depth and competitive ability of two North American C4 grasses in a greenhouse experiment. Changes in dry mass were determined and competitive intensity was calculated for both species. Species were grown separately or together in pots 30, 90, or 180 cm deep. When grown in monoculture, Schizachyrium scoparium total and belowground dry mass increased from the 30 to 90 cm depth, with no further significant increase from 90 to 180 cm. Aboveground dry mass did not increase significantly with depth. Total dry mass of Buchloe dactyloides increased significantly with depth when grown in monoculture. Aboveground dry mass increased from 30 to 90 cm depth but not from 90 to 180 cm. Belowground dry mass of B. dactyloides did not increase significantly with depth. In 180 cm pots, 53% of S. scoparium root dry mass was in the top 30 cm;74% of B. dactyloides root dry mass was in the top 30 cm. Roots of B. dactyloides were not found deeper than 90 cm. Aboveground dry mass of S. scoparium was not different in mixture or monoculture at any depth. Buchloe dactyloides aboveground dry mass in mixture was significantly lower than monoculture at the 30 cm depth, but not at 90 or 180 cm. The greatest competitive intensity was in the shallow soil pots. Soil depth could partially explain mosaics found in C4 grasslands where both species were found together with S. scoparium on deeper soils and B. dactyloides on shallower soils.展开更多
野牛草(Buchloe dactyloides)是原产于北美草原的多年生暖季型牧草,自引种至我国后一直广泛栽植于我国西北及华北地区,其种属资源丰富,育种潜力巨大,但国际植物新品种保护联盟(International Union for the Protection of New Varieties...野牛草(Buchloe dactyloides)是原产于北美草原的多年生暖季型牧草,自引种至我国后一直广泛栽植于我国西北及华北地区,其种属资源丰富,育种潜力巨大,但国际植物新品种保护联盟(International Union for the Protection of New Varieties of Plants,UPOV)及我国均无野牛草特异性、一致性和稳定性(Distinctness,uniformity,stability,DUS)测试指南。为了合理利用与保护野牛草种质资源,本研究依据UPOV以及我国相关文件规定标准,经过连续多年对8个进口商业品种、7个自主培育新品种、41个多年稳定品系共56份野牛草种质资源性状进行观测,系统性研究了野牛草表型性状的分布特点,确定了28个测试性状,包括雄花长度、种包千粒重等24个必测性状和枯黄期等4个辅助测试性状的判定标准,并在此基础上研制适应我国野牛草的DUS测试指南内容。本指南为我国野牛草性状测试、新品种的授权提供了测试技术的支撑,对今后野牛草新品种选育具有重大意义。展开更多
[Objective] This study aimed to investigate the mutagenic effect of 60 Co γ-rays irradiation on turf characteristics of Buchloe dactyloides （Nutt.） Engelm. [Method] Buffalo grass were irradiated with 60 Co γ-rays ...[Objective] This study aimed to investigate the mutagenic effect of 60 Co γ-rays irradiation on turf characteristics of Buchloe dactyloides （Nutt.） Engelm. [Method] Buffalo grass were irradiated with 60 Co γ-rays at five different radiation intensities （1 200, 1 400, 1 600, 1 800, 2 000 Gy） to determine the related turf characteristics and analyze the mutagenic effect of 60 Co γ-rays at different radiation intensities on buffalo grass. [Result] Germination rates of buffalo grass irradiated by different radiation intensities of 60 Co γ-rays varied inconsistently, and the root length and bud length were shorter than the control; compared with the control, the height of irradiated seedlings was significantly reduced, and the number of tillers, plant height, leaf length and leaf blade width were smaller than the control; however, the stolon length, stolon diameter and number of stolon nods had no significant difference compared with the control. [Conclusion] This study laid foundation for determining the appropriate radiation intensity of 60 Co γ-rays and selecting useful mutants of buffalo grass.展开更多
文摘The presence of grassland biomes and species cannot be predicted by examining bottom up causes such as precipitation and temperature. Top down causes including herbivory and fire seem to be major controlling aspects with other factors secondary. We examined soil depth and competitive ability of two North American C4 grasses in a greenhouse experiment. Changes in dry mass were determined and competitive intensity was calculated for both species. Species were grown separately or together in pots 30, 90, or 180 cm deep. When grown in monoculture, Schizachyrium scoparium total and belowground dry mass increased from the 30 to 90 cm depth, with no further significant increase from 90 to 180 cm. Aboveground dry mass did not increase significantly with depth. Total dry mass of Buchloe dactyloides increased significantly with depth when grown in monoculture. Aboveground dry mass increased from 30 to 90 cm depth but not from 90 to 180 cm. Belowground dry mass of B. dactyloides did not increase significantly with depth. In 180 cm pots, 53% of S. scoparium root dry mass was in the top 30 cm;74% of B. dactyloides root dry mass was in the top 30 cm. Roots of B. dactyloides were not found deeper than 90 cm. Aboveground dry mass of S. scoparium was not different in mixture or monoculture at any depth. Buchloe dactyloides aboveground dry mass in mixture was significantly lower than monoculture at the 30 cm depth, but not at 90 or 180 cm. The greatest competitive intensity was in the shallow soil pots. Soil depth could partially explain mosaics found in C4 grasslands where both species were found together with S. scoparium on deeper soils and B. dactyloides on shallower soils.
文摘野牛草(Buchloe dactyloides)是原产于北美草原的多年生暖季型牧草,自引种至我国后一直广泛栽植于我国西北及华北地区,其种属资源丰富,育种潜力巨大,但国际植物新品种保护联盟(International Union for the Protection of New Varieties of Plants,UPOV)及我国均无野牛草特异性、一致性和稳定性(Distinctness,uniformity,stability,DUS)测试指南。为了合理利用与保护野牛草种质资源,本研究依据UPOV以及我国相关文件规定标准,经过连续多年对8个进口商业品种、7个自主培育新品种、41个多年稳定品系共56份野牛草种质资源性状进行观测,系统性研究了野牛草表型性状的分布特点,确定了28个测试性状,包括雄花长度、种包千粒重等24个必测性状和枯黄期等4个辅助测试性状的判定标准,并在此基础上研制适应我国野牛草的DUS测试指南内容。本指南为我国野牛草性状测试、新品种的授权提供了测试技术的支撑,对今后野牛草新品种选育具有重大意义。
基金Supported by National Science and Technology Support Project of China (2009BADA7B04, 2011BAD17B01-02)National 973 Project of China (2012CB215300)+1 种基金National 863 Project of China (2012AA101201)National Pasture Modern Industry Technology System of China (CARS-35)~~
文摘[Objective] This study aimed to investigate the mutagenic effect of 60 Co γ-rays irradiation on turf characteristics of Buchloe dactyloides （Nutt.） Engelm. [Method] Buffalo grass were irradiated with 60 Co γ-rays at five different radiation intensities （1 200, 1 400, 1 600, 1 800, 2 000 Gy） to determine the related turf characteristics and analyze the mutagenic effect of 60 Co γ-rays at different radiation intensities on buffalo grass. [Result] Germination rates of buffalo grass irradiated by different radiation intensities of 60 Co γ-rays varied inconsistently, and the root length and bud length were shorter than the control; compared with the control, the height of irradiated seedlings was significantly reduced, and the number of tillers, plant height, leaf length and leaf blade width were smaller than the control; however, the stolon length, stolon diameter and number of stolon nods had no significant difference compared with the control. [Conclusion] This study laid foundation for determining the appropriate radiation intensity of 60 Co γ-rays and selecting useful mutants of buffalo grass.
