早熟禾种质资源及其遗传改良研究进展

 对国内外早熟禾种质资源概况、资源利用与评价、生物学特性、资源遗传改良及生物技术应用进展等进行了系统综述,并对目前存在的主要问题及如何解决提出相应的策略。早熟禾资源在中国蕴藏量极为丰富,其中有许多种类已成为世界公认的优良冷季型草坪草。草地早熟禾(Poa pratensis L.)是应用最多的草坪草,美国等注册的大量改良品种占据着世界种业市场;加拿大早熟禾(P. compressa L.)、糙茎早熟禾(P. trivialis L.)及一年生早熟禾(P. annua L.)可作为固土护坡等生态环保特殊用途的草种。国内对引进资源的研究主要集中在抗性生态适应和观赏性评价上,并编制了新品种培育的国内规范标准。目前对早熟禾资源研究的热点是围绕早熟禾特殊的兼性无融合生殖方式进行基础研究和生物技术改良,认为多倍体无融合品种受多源显性等位基因控制,通过组培和转基因手段对获得的再生体系进行改良取得了显著成就,但应加强转基因植株的应用研究及国有资源的基础研究和开发。     

四种草地早熟禾抗盐碱生理生化特性的研究

对北方草坪建植中常用的四个草地早熟禾（Poa Pratensis）品种进行了萌发期及苗期耐盐碱能力的比较研究。结果表明：低浓度混合盐碱处理对草地早熟禾的萌发和生长起到促进作用；随混合盐碱浓度的升高草地早熟禾的发芽率和生长受到明显的抑制，且对胚根生长的抑制作用强于胚芽；对幼苗进行混合盐碱胁迫发现，低浓度盐碱胁迫使SOD、CAT和POD的活性以及游离脯氨酸含量均升高，且在中等浓度下达到最高值，高浓度处理则开始下降；随着盐碱处理浓度的增大，MDA的含量也在缓慢增加。综合分析表明，四个草地早熟禾品种耐盐碱能力依次为：午夜>巴林>巴润>优异。     

不同硝酸钾用量对早熟禾生长性状的影响

为了探索促进黑龙江大庆地区早熟禾(Poa pratensis L.)健壮生长的施肥方式,比较了施用KNO3复合肥0(对照)、116.50、138.20、161.30kg/hm2后早熟禾在不同时期的鲜重、含水量、叶绿素a、b和类胡萝卜素含量。结果表明,早熟禾鲜重随着KNO3施用量增加而增加,161.30kg/hm2处理整个试验期间均显著(P0.05)高于对照,植株含水量6、10月份116.50~161.30kg/hm2处理高于对照,7、8月161.30kg/hm2显著高于对照;整个试验期间,161.30kg/hm2处理叶绿素a、b和类胡萝卜素含量均显著高于对照。综合分析认为161.30kg/hm2处理可以显著改善早熟禾生长性状。     

Effects of gravel mulch on aeolian transport:a field wind tunnel simulation

The shape,size and coverage of gravels have significant impacts on aeolian sand transport.This study provided an understanding of aeolian transport over the gravel mulching surfaces at different wind velocities by means of a mobile wind tunnel simulation.The tested gravel coverage increased from 5% to 80%,with a progressive increment of 5%.The gravels used in the experiments have three sizes in diameter.Wind velocities were measured using 10 sand-proof pitot-static probes,and mean velocity fields were obtained and discussed.The results showed that mean velocity fields obtained over different gravel mulches were similar.The analysis of wind speed patterns revealed an inherent link between gravel mulches and mean airflow characteristics on the gravel surfaces.The optimal gravel coverage is considered to be the critical level above or below which aeolian transport characteristics differ strongly.According to the present study,the optimal gravel coverage was found to be around 30% or 40%.Threshold velocity linearly increased with gravel coverage.Sand transport rate first increased with height above the wind tunnel floor(Hf),reaching a peak at some midpoint,and then decreased.     

9个野生早熟禾对低温胁迫的生理响应及苗期抗寒性评价

以甘肃省境内采集的9个野生早熟禾（Poa）为试验材料,设5,0,-5,-10℃共4个温度处理,探讨其对低温胁迫的生理响应和抗寒性,为抗寒早熟禾种质材料筛选和新品种选育提供依据。结果表明：随着温度下降,各材料的叶片相对膜透性逐渐增大,游离脯氨酸（Pro）、可溶性糖（SS）、可溶性蛋白（SP）、丙二醛（MDA）含量逐渐增加,超氧化物歧化酶（SOD）和过氧化物酶（POD）活性逐渐增强。运用隶属函数法综合评价9个材料苗期抗寒性发现,一年生早熟禾（P. annua）抗寒性最强,小药早熟禾（P. micrandra）、草地早熟禾（天祝）（P. pratensis）和草地早熟禾（甘南）抗寒性中等;硬质早熟禾（P. sphondylodes）、波伐早熟禾（P. poophagorum）、草地早熟禾（肃南）、草地早熟禾 （渭源）、草地早熟禾（兴隆山）抗寒性弱。相关性分析表明,SP含量与抗寒综合评价值极显著正相关（P<0.01）,POD活性与抗寒综合评价值显著正相关 （P<0.05）,Pro含量、SS含量、SOD活性、海拔与抗寒综合评价值成正相关,相对膜透性、MDA含量和年均温与抗寒综合评价值成负相关。     

津奥啉诱导草地早熟禾雄性不育的初步研究

通过津奥啉(SC2053)化学杀雄剂诱导草地早熟禾雄性不育试验的结果表明:供试的3个草地早熟禾品种在生育期幼穗长0.5～1.2cm时分别喷施剂量为5ml/L,6ml/L和7ml/L的SC2053化学杀雄剂,山峰草地早熟禾雄性不育率分别为90%,94%和97%;公园草地早熟禾分别为98%,100%和100%;巴润草地早熟禾分别为95%,98.5%和100%。除在7ml/L的剂量下,巴润草地早熟禾的小穗数与其他处理差异显著外,3个供试品种在不同剂量下穗长与小穗数差异均不显著。     

草地早熟禾牧草生长的气象条件分析

根据新疆乌鲁木齐市牧业气象试验站牧草观测资料,对草地早熟禾牧草生长期、生长高度和产草量的气候条件进行了分析,以期为开展牧业气象服务提供依据.     

刈割对青海早熟禾再生性的影响

通过对青海草地早熟禾不同刈割强度下再生性的研究,结果表明:刈割高度与频度不同,牧草再生能力不同。低茬高频的刈割,即留茬高度5cm、刈割频度7天/次,青海草地早熟禾再生性达到最佳水平,产草量也随之增加。     

北京地区早熟禾属植物种质资源研究

为收集优良的草坪种质资源,对北京地区野生早熟禾属(Poa L.)植物资源进行了实地考察。北京共有早熟禾属植物20种1个亚种,其中7个种及1个亚种为新分布,西部和北部山区早熟禾属植物物种分布较为丰富,尤其是东灵山、百花山、海坨山及喇叭沟门。从垂直分布看,草地早熟禾(Poa pratensis L.)为广布种,从平原到高海拔地区均有分布。硬质早熟禾(Poasphondylodes Trin.)在低山区常见,其他物种主要分布在海拔1000 m以上的地区。通过研究23份来自不同居群的草地早熟禾花序特征,发现不同居群的花序性状间存在较大的变异,花序基部最短分枝长的变异最大,花序小穗数次之。     

Ecological characterization of supina bluegrass (Poa supina Schrad.) germplasm from the Italian Alps

A collection was carried out in the Italian Alps to gather local genetic resources and acquire information on the ecological adaptation of supina bluegrass (Poa supina Schrad.), a cool‐season grass native to the Alpine region in Europe. It has potential for pastures and a growing interest for turfs, owing to excellent traffic, shade and cold tolerance. Available germplasm for research and breeding is scant, and extensive collections are needed to enable further development of adapted materials. Alpine germplasm has already proved valuable for breeding at lower altitude in pioneering selection work carried out in Germany. Extensive exploration throughout different environments, mostly above 1600 m elevation, yielded fifty‐five novel populations. Collections largely occurred in environments exposed to heavy disturbance by livestock, but it was also frequently found on very poor substrates along mountain paths and dirt roads, or around buildings. Some populations were present locally in shaded environments. Preliminary ex‐situ observations indicated likely among‐population variation to occur for important traits of breeding relevance such as disease and drought tolerance. Genetic variation for adaptive traits, although unproven, is hypothesized given the diversified habitats where the species was collected across the Italian Alps.