低温对假俭草叶片中渗透调节物质的影响

[目的]探讨自然低温条件下假俭草叶片中渗透调节物的变化及其与植物抗寒性的关系。[方法]以暖季型草坪草假俭草“翠绿1号”为试材,采用裂裂区设计,按钾肥、磷肥和多效唑3因素3水平组配27个处理组合对盆栽假俭草进行综合处理．比较不同处理组合对假俭草渗透调节物质的影响。[结果]在自然低温胁迫下,27个处理组合之间的假俭草叶片中渗透调节物质（可溶性糖和脯氨酸）含量的变化均达到了极显著性,在A2B2C2（即钾肥7．5g／L、磷肥8．0g／L、多效唑1．2mg／L）处理下,假俭草的叶片细胞中渗透调节物质含量相对较高,可延缓植株衰老并延长草坪草的青绿期。[结论]在自然低温下,肥料和生长素的较优搭配能促进渗透调节物质在假俭草草坪草中的大量积累,为延缓假俭草冬季枯黄和提前返青提供保障。     

四棱豆绿肥营养元素含量及品质评价

对17份四棱豆绿肥N、P、K、Ca、Mg、S、Fe、B、Mn、Cu、Zn、Mo、Cd、Cr、Hg、Pb、As营养元素含量进行分析评价。结果表明,四棱豆是含N、P、K高的优质绿肥,且中微量元素含量丰富,重金属含量低。根据综合评价,17份四棱豆均属于二级或三级有机肥。     

低温胁迫对油棕幼苗光合作用及叶绿素荧光特性的影响

在30 μmol/(m2.s)的弱光条件下,以25℃、10℃、7℃、4℃、1℃各处理油棕幼苗3天,测定了油棕幼苗叶片光合参数及叶绿素荧光参数的变化。结果表明：温度由 25℃降至4℃,净光合速率（Pn）显著下降的同时,气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度（Ci）也显著下降,但气孔限制值(Ls)和水分利用效率(WUE)却显著增加,说明光合作用的下降主要由气孔因素引起;之后随温度下降至1 ℃,净光合速率、气孔导度、蒸腾速率、水分利用效率、气孔限制值均出现显著下降,但胞间CO2浓度却显著上升,说明光合作用的下降主要由非气孔因素引起。叶绿素荧光参数显示,随温度下降,初始荧光(Fo)不断上升,PSⅡ最大光化学效率（Fv/Fm）、光化学猝灭系数(qP)、非光化学猝灭系数（qN）不断下降,其中以4 ℃以下的低温胁迫,这些参数的变化最为显著。表明严重低温对油棕幼苗产生了显著的光抑制,过剩的激发能不能通过热耗散途径散失,大量积累于PSⅡ反应中心,使光合机构遭受了较大程度的破坏,最终导致油棕幼苗光合能力的急剧降低。     

喷施氯化钾对油菜植株硝酸盐含量及氮素分配的影响

本试验采用土培试验,研究了茎叶喷施质量分数为1%的氯化钾溶液对油菜角果初期和收获期植株硝酸盐含量及植株氮素分配的影响。以喷施质量分数为1.17%的硫酸钾溶液（要求氯化钾和硫酸钾溶液中钾离子的物质的量浓度相同）和清水作相比较,在开花后期开始喷施,每两天喷洒一次,连续喷洒15天,喷洒部位在茎和叶,重点喷洒叶的背面,尽量不喷洒至叶柄,于角果初期和收获期采样。结果表明,喷施氯化钾溶液能有效降低开花期和收获期油菜茎叶硝酸盐含量,与喷施硫酸钾溶液和清水相比达到了显著水平;有效促进了氮素向角果和籽粒分配,显著增强了油菜角果初期叶片硝酸还原酶的活性;同一品种不同处理之间的差异比较显著,品种之间处理后的差异也比较明显。     

Forage soybean production for seed in mediterranean environments

Despite several experiments on row spacings and seeding rates of grain soybeans, limited information is available on the most suitable row spacing and seeding rate for tall and robust forage type soybeans grown for seed. The objectives of this study were to investigate seed yield, oil and protein content, and several morphological traits as affected by row spacing (20, 40, 60 and 80 cm) and seeding rate (330,000, 660,000, 990,000 and 1,320,000 seeds ha⁻¹) in tall and robust forage type soybeans in three irrigated Mediterranean environments in Turkey in a randomized split plot design with three replications in 2004 and 2005. Row spacings had no significant effect on plant height but tall and profusely branched plants developed in wide row spacing and light seeding conditions. Seed yield responded positively and linearly to row spacing up to 60 cm and then decreased slightly in all locations. Seed yield was the highest at 990,000 seeds ha⁻¹ seeding rate in all three locations (3072.5 kg ha⁻¹ in Bursa LSD = 214.7 kg ha⁻¹, 3295.1 kg ha⁻¹ in Mustafakemalpasa LSD = 298.6 kg ha⁻¹ and 3311.3 kg ha⁻¹ in Samsun LSD = 321.1 kg ha⁻¹). Averaged across years, locations, row spacings, and seeding rates the mean seed yield was an impressive 3013.4 kg ha⁻¹ compare with 3500.0 kg ha⁻¹ average seed yield of grain types. Crude protein and oil content of forage type soybean were not significantly affected by row spacings and seeding rates. It was concluded that forage type soybeans can be grown for multiple purposes at the 990,000 seeds ha⁻¹ seeding rate and 60 cm row spacings in Mediterranean environments.     

红茶菌－嗜酸乳杆菌对银合欢叶的发酵脱毒效果

以银合欢叶含羞草素降解为单一指标.利用红茶菌液、嗜酸乳杆菌液、保加利亚乳杆菌液及植物乳杆菌液为发酵菌液,对银合欢叶的脱毒效果进行研究.以便选取有效的脱毒菌.结果表明,红茶菌液与嗜酸乳杆菌菌液等比例混合液对银合欢叶含羞草素降解效果最好.当菌液接种量为8%,固体密封发酵30d.银合欢叶中含羞草素降解率能达到82%左右,降解效果明显.这为拓宽银合欢的应用具有一定意义.     

冰草根际蟋蟀草平脐蠕孢菌的研究

对冰草根际分离获得的蟋蟀草平脐蠕孢(Bipolaris eleusinea J.H.Peng et J.Y.Lu)的形态特征、培养性状及生物学特性进行研究,以期了解牧草根部平脐蠕孢菌的生长发育特点,并为该菌引起的牧草根病防治提供依据.结果表明:蟋蟀草平脐蠕孢分生孢子萌发的温度范围为5℃~40℃,适宜温度20℃~30℃;在各酸度下均能萌发,最适为pH 6.47;其分生孢子的萌发需要液态水,在相对湿度100%时分生孢子萌发率仅为3.2%,而相对湿度低于100%时孢子不萌发;低稀释倍数的土壤悬液、麦根浸出液、羊粪浸出液和蔗糖溶液[0]及高稀释倍数的麦根液和羊粪液均抑制孢子萌发,但高稀释倍数的土壤液和蔗糖液能促进孢子萌发;且孢子萌发对光不敏感.蟋蟀草平脐蠕孢菌丝生长的温度范围为10℃~40℃,最适25℃;碳源中D-木糖、氯醛糖对蟋蟀草平脐蠕孢菌生长具有明显抑制作用,而蔗糖、甘露糖和D-果糖对蟋蟀草平脐蠕孢菌丝生长具有明显促进作用;氮源中硝酸钠、亮氨酸对蟋蟀草平脐蠕孢菌丝的生长具有促进作用,而尿素等9种氮源均有抑制作用,并且此菌在含有各种碳、氮源的培养基上的菌落形态有差异.在国内首次报道此菌侵染冰草(Agropyron cristatum),为一新寄主植物.     

高寒地区暖季草场放牧牦牛的生产性能及其土壤养分变化

旨在通过不同放牧强度下高寒小嵩草(Alpine Kobresia parva(Nees)Wang et Tang ex Y.C.Yang)草甸和垂穗披碱草(Elymus nutans Griseb.)/星星草(Puccinellia tenuiflora(Griseb.)Scribn.et Merr.)高寒混播草地暖季草场植物初级生产力、土壤养分含量以及牦牛生产性能的研究,为草地合理利用提供有益的依据。结果表明:牦牛个体增重与放牧强度均呈线性关系;高寒小嵩草草甸暖季草场最适放牧强度为1.26头/hm²,垂穗披碱草/星星草混播高寒混播草地暖季草场的最适放牧强度是7.23头/hm²;放牧强度对高寒混播草地速效氮和速效磷的影响不显著,对速效钾的影响显著(P<0.05);随着放牧强度的提高,高寒小嵩草草甸土壤有机质、有机碳、全氮、全磷的含量呈减小趋势;当放牧强度分别达到1.07头/hm²,1.08头/hm²和1.22头/hm²时,0~5 cm,5~10 cm,10~20cm土壤速效氮含量依此达到最小;随着放牧强度的提高,高寒小嵩草草甸禾草和莎草的比例下降,可食杂草和毒杂草比例增加,而高寒混播草地垂穗披碱草的比例降低,星星草和杂类草的比例增加。     

Symptoms and histopathological study of Anoplophora glabripennis larvae infected with Metarhizium (Metsch.) Sorokin MS01

Some changes in color and morphology of Anoplophora glabripennis larvae were observed when infected with Metarhizium (Metsch.) Sorokin MS01. Paraffin sections show the spores of MS01 attached to the cuticle of A. glabripennis larvae at 24 h post inoculation (hpi). At 36 hpi, the conidium germinated and penetrated through the cuticle. After 48 h of inoculation, the endocuticle was disintegrated and the germ tubes passed through the epithelial layers into the hemocoel and multiplied, and then invaded the tissues near the penetration point, such as the fat body, muscle, tracheal tissue, malpighian tubule, alimentary canal, etc. The infected larvae were dead and most tissues and organs were infected and disintegrated with the multiplication of the mycelium for 3 days. The hyphae emerged through the cuticle and formed a hyphal layer on the surface of the dead insect and the conidium emerged five days after inoculation.     

水杨酸诱导黄瓜幼苗抗冷性的基因表达

水杨酸(Salicylic acid,SA)能诱导植物提高抗生物胁迫和非生物胁迫(冷胁迫等)的能力.为研究SA对非生物胁迫下植物基因表达的影响;以黄瓜("新优30")幼苗为试材,用SA(3 mmol/L,pH6.0)溶液和蒸馏水处理后,经7℃冷胁迫48 h,提取叶片总RNA并反转录cDNA,利用mRNA差异显示技术分离出12个差异表达cDNA片段.经反向斑点杂交验证其中2个(SICCL 1和SICCL 2)为高差异表达片段.序列测定和Blast分析表明,SICCL 1与甜瓜中黄瓜花叶病毒(Cucumber Mosaic Virus,CMV)相关基因AM734282有88%同源性;SICCL 2与毛柽柳中NaHCO,胁迫相关基因THL24h-106有86%同源性.由此推测,SA诱导植物抵抗生物胁迫和非生物胁迫的能力可能是通过诱导植物某些相同基因的表达来实现的.