扁穗牛鞭草人工种群构件及生物量动态变化

测定扁穗牛鞭草(Hemarthria compressa)人工割草地不同生长时期种群构件数量与分布、生物量结构变化,结果表明:在生育期内种群分蘖数呈现双“S”形变化,在再生初期与开花期二级分蘖数量大于一级分蘖,决定产量的一级分蘖在株高50cm时,数量达最大值3640蘖/cm,到孕穗期(株高约80cm)降为2840蘖/cm;单蘖与叶片数均呈双“S”形变化;单蘖叶面积呈“厂”形变化,而叶面积呈现出典型的双“S”形变化;单蘖和叶片生物量分别呈“n”和双“S”形变化;茎的数量与分蘖数变化一致,单蘖和茎生物量并非同步呈双“S”形变化;地上生物量在生育期内呈“S”形变化;牧草质量呈“直线”形下降。     

红豆草种子高产栽培管理技术

牧草种子在人工草地建设和草地改良中具有重要的作用.当前,草地改良、生态治理、环境绿化及农业结构调整等均需要大量的优良牧草种子.优良牧草种子是指不仅具有优良的性状表现,而且具有良好播种品质的种子.牧草种子的生产不仅要求较高的种子产量,更要保证获得品质优良的种子.牧草种子生产可通过适宜环境的选择和改善、田间栽培、管理技术的研究和应用来提高产量,特别是营养生长期的田间管理.因为只有满足了牧草营养生长期对温度、光照、养分和水分等条件的要求,才能有较高的种子产量.     

几个饲用燕麦品种比较试验研究

在川西北高寒牧区种植3个饲用燕麦材料,通过对其生长周期、产草量、农艺性状(茎叶比、叶长、叶宽等)的比较研究,结果显示:饲用燕麦新材料Y61-005在海拔3 500m以上的高寒牧区能充分利用夏季水热同步的优势,迅速进行营养生长和生殖生长,完成整个生育周期,比对照品种青引1号和丹麦444早熟近一个月,且干草产量(946.89 kg/667m2)比对照丹麦444高17.46%,差异显著;生长速率(2.18 cm/d)比对照青引1号和丹麦444分别高10.64%和17.32%;分蘖数达到4.85,分别比青引1号和丹麦444高38.57%和16.3%.试验结果表明:Y61-005在海拔3 500 m以上的川西北高寒牧区种植,表现出较好的农艺性状和较强的适应性.     

川西北高原野生花卉种质资源调查初报

通过对四川省红原县、若尔盖县、松潘县、九寨沟县和甘肃省玛曲县、碌曲县等地的考察,发现川西北高原野生花卉有70多种,含24科,58属,主要为草本花卉。并对川西北高原野生花卉观赏类型、花色等进行了简要统计分析,结果显示观花类有55种,观果类有11种,观叶类有6种;按花色紫蓝、黄、红、白分类,则蓝紫花种类最为丰富(22种)、黄花次之(18种)、白花较少(8种)、红花最少(7种),同时提出利用野生花卉资源的对策。     

越冬时葎草雌雄株生理反应和再生策略的差异分析

以野生雌雄葎草为材料,通过测定越冬前(12月1日)、越冬中(1月15日)和越冬后(4月15日)雌雄株构件中可溶性糖(SS)、淀粉(ST)、丙酮酸(PA)含量和硝酸还原酶(NR)活性,测定越冬后构件存活率和再生率及再生构件性状与生物量分配比,分析雌雄株越冬时生理反应和再生策略的差异。结果表明:1)越冬前雄株叶片中ST含量小于雌株而SS含量大于雌株,其成熟茎和根的SS和ST含量均小于雌株(P<0.05),雄株通过提高叶中SS含量抵御寒冷,雌株通过转移糖分到茎和根应对寒冷;2)越冬前雄株叶和茎的PA含量显著大于雌株,根中含量显著小于雌株(P<0.05),构件中NR活性无性别差异(P>0.05),雄株通过增强茎和叶的呼吸抵御寒冷,雌株通过根储备营养应对寒冷;3)越冬后雌株再生叶的SS和ST含量大于雄株(P<0.05),PA含量和NR活性小于雄株,其再生代谢基础高于雄株;4)越冬时雄株植株存活率为26.67%,为雌株植株存活率的34.78%,雄株存活植株的茎存活率仅为雌株的32.24%,越冬后雌株茎、叶再生率仅为雄株的21.03%和23.82%,而花序再生率高达74.40%;5)雌株再生叶数和叶面积及再生茎长小于雄株(P<0.05),其再生茎和叶生物量分配比仅0.59%和1.31%,再生花序分配达98.09%,其再生花序柄和花序轴长及小花数大于越冬前正常花序,且萼片面积增大且生物量分配比占31.26%,总面积达624.92 cm²·株^-1,为再生叶总面积的24.50倍。越冬时雄株通过生理反应抵御寒冷,使茎和根贮藏物质低于雌株,故其存活率和再生率低于雌株。越冬后雄株再生生物量仅1.57 g·株^-1全部分配到营养器官,雌株再生总生物量达32.05 g·株^-1,且98.09%分配到花序,萼片代替叶片为主要光合器官,为花序形成和开花就近提供养分。     

Effects of slope on soil properties and post construction desertification of highway embankments in an Alpine Meadow region北大核心CSCD

This research investigated effect of slope on the performance of highway embankment soil properties post construction, as there is a demand for technical data of this nature to underpin the design of highway revetment work in alpine meadow regions of China. A section of national road G248 in Northwest Sichuan Alpine Grassland, built 10 years ago, was identified as a study site and plots were marked out for sampling on five slope classes: gentle slope, 6°-15° (GS); moderate slope, 16°-25° (MS); steep slope, 26°-35° (SS); very steep slope, 36°-45° (VS); extreme slope, >45° (ES). Undisturbed flat natural grassland >10 m distant from the roadbed was used as the control (CK). Measurements conducted included determination of particle size composition, physical and chemical parameters of the soils, vegetation cover and the proportion of the plot area exhibiting degradation or desertification. The relative reduction rate of organic matter and total nitrogen was also determined, and differences in soil water content and fertilizer retention capacity were assessed. It was anticipated these data would provide a basis for the construction of ecologically sound slope protection structures in alpine regions. It was found that: 1) Increased slope significantly decreased the proportion of clay and silt particles and increased the proportion of coarse sand and small stones (P<0.05). The greater the slope, the greater the soil bulk density and pH value, and the lower the soil water content. 2) Slope facilitated leaching of soil carbon fractions with the leaching intensity of the fractions ranking soil organic matter (SOM)>total carbon (TC)>inorganic carbon (IC)>dissolved organic carbon (DOC). For example, SOM levels were, respectively, 115, 92, 72, 30, 9 and 3 mg·kg−1 for CK, GS, MS, SS, VS, and ES slope classes while DOC levels ranged from 35.4 mg·kg−1 in CK to 9.2 mg·kg−1 in ES. 3) The ranking for the effects of slope on various soil fertility measures was: effective N>alkali-hydrolysable N>total N>available K> available P>total K>total P. Thus, available N was more easily lost than total N and alkali-hydrolysable N. Available N levels declined progressively across slope classes from 236 mg·kg−1 in CK to 6.3 mg·kg−1 in ES, while total N and alkali-hydrolysable N showed marked loss between GS and VS slope classes. A slope threshold for sharp increase in loss of total P and available P was observed between GS and MS slope classes. With increase in slope gradient, the total K increased, while the available K content decreased. 4) With respect to the influence of slope on the degree of desertification: for CK and GS >90% of the plot area was classed as non-desertified; for GS 79% of the plot area was moderately or severely desertified; for SS, VS and ES, 79, 86 and 94%, respectively, of the plot area was severely or extremely severely desertified. The proportion of severe desertification increased markedly at > 15° slope (i. e. MS) and the proportion of extremely severe desertification increased markedly at >25° slope (i. e. SS). 5) When the slope effects were expressed in relative terms, the relative increase in desertification was high and changed little at slopes >15°, while the relative decreases in organic matter and total nitrogen were high and changed little once slope exceeded 25°. As slope angle increased, relatively low rate of total coverage percentage and powder particles <0.02 mm and the relative increase rate of sand particles >0.05 mm increase significantly. In summary, as slope of the study plots increased, fine sand, silt and clay particles were progressively lost, soil fertility progressively declined, and the degree of desertification increased markedly. Therefore, the technical plan for ecologically sound slope protection in highway construction should be formulated according to the steepness of the slope. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

虉草属草种质资源研究进展

虉草属(Phalaris Linn.)系禾本科一年生或多年生草本植物,广泛分布于北半球的温带地区,大部分产于欧美。其植株高大、生长速度快、且具有高生物质产量,具有多种用途,经济价值较高,广泛用于牧草、造纸、生物质能源和水土保持等方面。本文从!草属植物生物学特性与分布、遗传多样性、品种选育、栽培与利用、抗营养因子生物碱等方面进行综述,并提出了研究展望,以期为虉草属草种质资源的进一步研究提供参考。     

川西北高原野生老芒麦居群穗部形态多样性研究

对采集自川西北高原的13个野生老芒麦居群的15项穗部形态指标进行了研究。Shannon-weaver指数分析表明,13个居群在穗部性状上具有丰富的遗传多样性(H′=1.793 7),且居群内遗传变异(69.31%)大于居群间(30.69%);聚类分析将这13个居群分为3组;主成分分析表明单穗长和宽、单穗重、小穗长、内外稃长和每穗轴节小穗数等是造成13个居群老芒麦穗部特征差异的主要因素;相关分析的结果表明海拔、纬度、经度和降水量对川西北高原野生老芒麦居群穗部性状变异贡献较大,而年均温对此影响不大。此外,提出了川西北高原野生老芒麦的保护策略。     

川西北高原老芒麦的遗传多样性研究

以老芒麦品种川草1号和川草2号为对照,采用酸性聚丙烯酰胺凝胶电泳(A-PAGE)方法对采自川西北高原的36份野生老芒麦(Elymus sibiricw L.)种质和5份老芒麦新品系进行了遗传多样性分析.从供试材料中共分离出了42条醇溶蛋白条带,4个电泳分区(α、β、γ、ω)的多态性带数分别为9、10、8和12条,多态率达92.86%;材料间的Nei-Li遗传相似系数(GS)的变异范围为0.333 3～0.956 5,平均值为0.6196.说明供试老芒麦材料具有较为丰富的醇溶蛋白遗传多样性.对所有材料的聚类分析和主成分分析发现.在GS值为0.636的水平上供试材料可聚成5个大类,来自同一地区的老芒麦基本聚在同一类.呈现出一定的地域性分布规律.几个老芒麦新品系间的遗传多样性水平较低,醇溶蛋白条带多态率为48.00%.相似系数变异范围为0.648 6～0.956 5,且在聚类分析和主成分分析中单独聚为一类,说明老芒麦新品系和野生种质间存在较大的遗传差异.     

不同添加剂对高水分全株玉米青贮饲料发酵品质和细菌群落的影响

为探讨不同添加剂对高水分全株玉米(Zea mays L.)青贮饲料发酵品质和细菌群落的影响,本试验以乳熟期的全株玉米为原料,设置对照、添加苯甲酸钠和植物乳杆菌3个处理,青贮60 d后,测定其营养成分、发酵指标和细菌群落组成.结果表明:植物乳杆菌和苯甲酸钠均能使高水分全株玉米青贮饲料的细菌群落发生一定变化,并以乳杆菌属细...