新疆棉花黄萎病菌营养体亲和性研究

１９９６－１９９８年从新疆各主要植棉区采集３０个野生型棉花黄萎病菌菌株,陕西省植保所提供Ｔ－９、ＶＤ－８、安阳菌株及泾阳菌株,经在ＷＡＣ培养基上诱发培养,３４１个突变体,其中１１４个为ＮｉｔＭ,占２６．４５％,３１７个为Ｎｉｔｌ,占７３．５５％。经营养体亲和性配对测试,３２个菌株可分为２个营养亲合群（ＶＣＧｓ）,Ｔ－９与ＶＤ－８属于亲合群Ｉ（ＶＣＧ１）,其余３０个菌株属于亲合群Ⅱ（ＶＣＧ２）,即落     

沙芥营养生长规律及叶片解剖结构的研究

通过对沙芥营养生长期的生育规律及叶片不同生育期解剖结构的研究,分析了沙芥的生长特点及叶片结构与功能的关系,为人工驯化栽培和开发利用提供科学的理论依据。结果表明:沙芥营养生长生育期为(130±4)d其生育期可划分为发芽期、幼苗期、旺盛生长期和生长衰退期4个时期;沙芥叶片进化为适应干旱的高光效的环栅型叶,输导组织发达,机械组织不发达,叶表皮由表皮和副表皮2层细胞组成;很多表皮细胞特化为大型的储水的泡状细胞密布于叶表,沙芥叶表气孔下陷,且有较大的气孔下室。     

不同玉米品种生物产量和营养物质产量的差异分析

（中国农业大学动物营养学国家重点实验室,北京 100094）     

紫花苜蓿营养生长与生殖生长调控

主要研究了播种行距,灌水量,N、P、K肥施用量,植物生长延缓剂,微肥,干燥剂对甘农3号紫花苜蓿(Medicago sativa L.cv.Gannong No.3)(简称苜蓿)营养生长和生殖生长的影响,及其种群的生长冗余。     

霍山石斛营养器官的解剖结构

对安徽省霍山县生长的两个石斛商品药材中的上品－霍山石斛和铁皮石斛的营养器官解剖结构特征作了探讨,为深入研究石斛的生物学特性和生药鉴定提供基础资料。     

植被类型对黄土高原土壤侵蚀的影响研究

根据辛店沟1955～1959年坡面径流小区的观测资料,分析了不同植被(高粱豇豆、苜蓿、草木樨)被覆度对土壤侵蚀的影响,主要为被覆度(C)与侵蚀速率的关系。结果表明土壤侵蚀速率随被覆度的增加呈指数下降。不同植被对土壤侵蚀速率的影响不同,应用USLE(The Universal Soil Loess Equation)分别模拟了3种不同植被被覆度对土壤侵蚀的关系方程,探讨了植被被覆度对土壤侵蚀的作用规律。     

不同肥料配比对大花蕙兰“YX52”生长的影响

在同种基质条件下,研究不同肥料配比500mg/kgK2SO4复合肥(处理1)、500mg/kgKH2PO4+1000mg/kgCO(NH2)(2处理2)、500mg/kgK2SO4复合肥+缓释肥(处理3)、500mg/kgKH2PO4+1000mg/kgCO(NH2)2+缓释肥(处理4)对大花蕙兰品种"YX52"(星月)生长的影响。结果表明:处理4对植株营养生长及提高叶绿素含量效果最为显著,处理4与处理3能缓解高温对大花蕙兰植株生长的不利影响。这说明在使用缓释肥基础上,喷施500mg/kgKH2PO4+1000mg/kgCO(NH2)2有利于大花蕙兰的生长,可作为在大花蕙兰生产经营中施肥的辅助措施;500mg/kgK2SO4复合肥与500mg/kgKH2PO4+1000mg/kgCO(NH2)2由于营养元素单调,不能满足大花蕙兰生长所需的养分;而500mg/kgK2SO4复合肥+缓释肥不能用于生产。     

Propagule Quantity and Quality in Traditional Makushi Farming of Cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis>): A Case Study for Understanding Domestication and Evolution of Vegetatively Propagated Crops

Modeling how crop plants evolve under domestication requires estimating among-plant variation in important parameters of the reproductive system, including fecundity – the number of propagules produced – and propagule quality. Measuring these traits poses particular problems in vegetatively propagated crop plants. Unlike seeds, vegetative propagules are not intrinsic biological entities but are prepared by farmers. Propagule number and quality are thus determined by the interaction between plant traits and how farmers prepare propagules. We conducted observations, interviews and experiments to study this interaction in cassava grown by Makushi Amerindians, examining how both sources of variation, in plant traits and in farmers’ practices, combine to determine the number and quality of propagules produced. Increased stake mass, determined mostly by stem diameter, leads to increased yield and also to increased asexual ‘fecundity’ of the resulting plant. Farmers’ practices reflect knowledge of this relationship. Diameter is the key criterion in the selection of stems for stakes. Larger diameters are preferred; when thinner stems are used, stakes are cut longer, partially compensating for reduced mass. These results suggest that conscious and unconscious selection to increase ‘fecundity’ and propagule quality in cassava would act to favor plants with thicker stems. Mean stem diameter is greater, and variation in stem diameter is lower, in little-branched plants. Selection for increased asexual ‘fecundity’ can thus have led to reduction in the degree of branching, one of the most striking differences between domesticated cassava and its wild ancestors. Measuring variation in asexual fecundity is a key step in analyzing evolution of the mixed clonal/sexual reproductive systems that characterize many vegetatively propagated crop plants.     

桃树枝插生根的研究

桃茎插条内不定根原基起源于形成层。生根期间淀粉含量下降,IBA处理能促进淀粉含量的下降。在愈伤组织和根原基形成过程中,内源生长素含量下降,在根突出前内源生长素含量上升达高峰;根突出后又下降。经IBA处理的插条生根过程中内源脱落酸含量持续下降。 9月份采集的,经2500ppmIBA处理的插条,生根率高,达87.5％;不经贮藏的硬枝插条生根率低,仅为10％,经过两个月的低温藏贮后,生根率提高到60％。插床底温应控制在12—17℃范围内,以12°为佳。     

不同氮效率玉米杂交种的营养生长及光合特征

以氮效率不同的4个玉米杂交种(组合)为材料,在两个氮水平下分析了营养生长及光合特征。结果表明,施氮条件下玉米营养体的含氮量平均在2.0%左右,低氮处理下降到1.5%左右;氮高效品种的穗位叶光合效率并没有降低,氮低效品种的叶片光合效率则显著降低。氮高效品种在叶片保绿性方面明显具有优势,在低氮条件下保持了较大的绿叶面积和较高的叶绿素含量。这些特征保证了氮高效品种后期光合产物供应能力强,并用于子粒灌浆。