老芒麦衰老过程形态特征变化规律及对养分添加的响应  

Phenotype changes during aging over six years of Elymus sibiricus stands and the effects of nutrient addition

作　　者：张永超[1] 魏小星[1] 梁国玲[1] 秦燕[1] 刘文辉[1] 贾志锋[1] 刘勇[1] 马祥[1] ZHANG Yong-chao;WEI Xiao-xing;LIANG Guo-ling;QIN Yan;LIU Wen-hui;JIA Zhi-feng;LIU Yong;MA Xiang(Key Laboratory of Superior Forage Germplasm in the Qinghai-Tibetan Plateau,Qinghai Academy of Animal Science and Veterinary Medicine,Qinghai University,Xining 810016,China)

机构地区：[1]青海省青藏高原优良牧草种质资源利用重点实验室,青海省畜牧兽医科学院,青海大学,青海西宁810016

出　　处：《草业学报》2022年第6期101-111,共11页Acta Prataculturae Sinica

基　　金：青海省科技厅基础研究项目(2018-ZJ-968Q);牧草体系海北综合试验站(CARS-34)资助。

摘　　要：试验以青藏高原青海省高寒草地中广泛分布和退化草地补播改良中的常用牧草品种-‘青牧1号’老芒麦为研究对象,在青藏高原东北部,青海湖湖东地区设置1龄到6龄老芒麦自然生长田,6龄老芒麦施肥田和老芒麦连续施肥田(6年)的3个处理,测定老芒麦地上生物量和穗部特征并进行比较分析。结果表明:青牧1号老芒麦2龄和3龄地上生物量较高,3龄后逐年降低。青牧1号老芒麦地上生物量变化情况,可以分为4个阶段,1龄期,2~3龄期,4~5龄期和6龄期。老芒麦单穗重从2龄到5龄逐渐增加,6龄显著性降低。青牧1号老芒麦从2龄到5龄,单株穗重占比逐渐升高,6龄开始降低。6龄田施用氮肥和磷肥均显著提高了老芒麦地上生物量,氮肥增产效果优于磷肥。高氮(N_(75))处理下6龄老芒麦地上生物量最高。6龄青牧1号老芒麦单穗重在N_(60)处理下最高。长期施肥可有效提高老芒麦地上生物量,N_(60)P_(75)处理下地上生物量最高,在N_(75)P_(75)处理下6龄老芒麦单穗重最高。长期不施肥,6龄老芒麦茎重比例最高。N_(45)P_(90)长期施肥处理下,茎秆重量比例下降,穗重和叶重比例相对增加明显。N_(60)P_(90)和N_(75)P_(75)长期施肥处理下,也可有效提高单株老芒麦穗重的比例。In this study,stands of Elymus sibiricus cv.Qingmu No.1(which is widely distributed and used in the grasslands of Qinghai Province on the Qinghai-Tibetan plateau)were studied.Three field experiments were set up;namely the normal growth over years one to six from establishment of Qingmu No.1 without fertilizer application,the effect of fertilizer addition to six year old stands and annual fertilizer application over the six year experiment.The aboveground biomass and characteristics relevant to seed production or plant growth,such as specific leaf area were recorded and the effect of fertilizer in the two fertilizer treatments were analyzed.It was found that the aboveground biomass increased from one to three years old and peaked at two-three years old,and then decreased from three years old onwards.We identified four developmental stages over the six-year experiment period:in the first year the initial growth and establishment stage;at two-three years old,the maximum biomass stage;at four-five years old,the decline stage and at six years old and beyond,the aging stage.The single ear weight increased year by year up to five years of age then decreased significantly in the sixth year.The ear dry weight as a proportion of above ground biomass showed the same trend as the single ear weight.In six year old plots of E.sibiricus,nitrogen and phosphorous addition increased the aboveground biomass significantly compared with the control treatment,and the effect of nitrogen was greater than the effect of phosphorous.The biomass of six year old E.sibiricus stands was much higher with the addition of 75 kg·ha^(-1) N than at lower rates of N.With the addition of60 kg·ha^(-1) N the single ear weight was much higher than at higher or lower rates of N.With annual fertilization,the aboveground biomass was significantly higher than the control which received no fertilizer.The aboveground biomass was highest under a treatment receiving 60 and 75 kg·ha^(-1) of N and P,respectively,and the single ear weight was highest under a tre

关 键 词：老芒麦 衰老 形态特征 繁殖策略 养分添加 

分 类 号：S543.9[农业科学—作物学]