PEG胁迫下3个多年生黑麦草品种抗性生理研究

利用不同浓度PEG-6000溶液对3个多年生黑麦草(Lolium perenne L.)品种进行不同程度的水分胁迫处理,研究不同浓度PEG处理对各品种叶内游离脯氨酸与丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和外渗率等生理性状的影响.结果表明:PEG胁迫处理下品种首相叶片相对含水量均最高,叶片外渗率均最低且MDA含量增幅较小,对渗透胁迫的抗性最强,而品种球道的抗旱性最弱;渗透胁迫下各品种叶内游离脯氨酸累积量都明显增加且在渗透胁迫加重时,品种首相叶内脯氨酸含量急剧上升,对渗透胁迫具有较强抵御能力;5%PEG浓度胁迫初期,各品种叶片SOD活性均有所提高,胁迫加重时SOD活性则呈现不断下降趋势;PEG渗透胁迫导致3个多年生黑麦草品种叶片相对含水量下降、细胞膜透性增大、MDA含量增加、脯氨酸含量上升而SOD活性下降,且3个品种对应指标的变化幅度存在差异.     

禾谷缢管蚜与内生真菌互作对醉马草幼苗的生理影响

通过测定一系列生理变化指标,研究人工接种条件下禾谷缢管蚜(Rhopalosiphumpadi (L.))对带内生真菌(E+)与不带菌(E-)醉马草(Achnatherum inebrians (Hance) Keng)幼苗的影响.结果表明:在一定时期内,禾谷缢管蚜刺吸可使醉马草幼苗叶片相对含水量和叶绿素含量显著降低(P<0.05),同一个虫口密度E+与E-植株之间差异显著(P<0.05);幼苗体内SOD活性和POD活性均随危害时间的延长而显著升高(P<0.05),同一个虫口密度E+与E-植株之间差异显著(P<0.05);接种蚜虫可使MDA和游离脯氨酸的含量显著提高(P<0.05),同一个虫口密度内E+与E-植株之间差异显著(P<0.05).综上所述,内生真菌的侵染可以在一定程度上间接影响禾谷缢管蚜取食,进而影响醉马草幼苗生理生化的变化.     

茄子嫁接抗黄萎病与叶片叶绿素含量、相对电导率和游离脯氨酸含量的关系

以野生茄子托鲁巴姆为砧木,以快圆茄为接穗,研究了茄子嫁接抗黄萎病与叶片叶绿素含量、相对电导率和游离脯氨酸含量的关系。结果表明:1)植株叶片中叶绿素含量为砧木>嫁接株>对照,差异达极显著水平,与发病率呈负相关趋势。2)植株叶片相对电导率和游离脯氨酸含量均为砧木<嫁接株<对照,差异达极显著水平,与发病率呈正相关趋势。     

稀土对小麦抗旱性影响机理初探

本文研究了稀土对植物抗旱性的影响，实验结果表明，稀土样与对照样的相比：随干旱天数增加，各种抗旱生理指标提高，植物抗旱性增加，越是干旱ＡＢＡ和Ｐｒｏ增加越快，蛋白质和ψｗ下隆越慢，抗旱性越强。     

四种结缕草属草坪草对土壤干旱胁迫的响应及抗旱性研究

在玻璃温室盆栽试验,以正常浇水为对照,测定土壤逐步干旱下4种结缕草属草坪草叶片相对含水量、质膜相对透性及脯氨酸含量的变化.结果表明,与对照相比,在干旱胁迫下4种草坪草叶片相对含水量下降,叶片质膜相对透性上升,脯氨酸含量剧增,但不同草种的变化幅度和进程不同.叶片质膜相对透性与叶片相对含水量呈显著负相关(P<0.05),与脯氨酸含量呈显著或极显著正相关(P<0.01).较严重干旱下相对含水量、相对电导率和脯氨酸含量不同草种间存在显著差异.干旱下草坪草的脯氨酸含量与抗旱性呈显著负相关.4种草坪草抗旱能力强弱的顺序为:兰引3号>细叶结缕草>沟叶结缕草>日本结缕草.复水试验草坪外观观测结果与草种抗旱性强弱基本一致.     

Serum biochemical parameters and amino acids metabolism are altered in piglets by early-weaning and proline and putrescine supplementations

The study was to investigate the effect of early-weaning stress and proline (Pro) and putrescine (Put) supplementations on serum biochemical parameters and amino acids (AA) metabolism in suckling and post-weaning pigs. Blood and small intestinal mucosa were harvested from suckling piglets at 1, 7, 14, and 21 d of age and piglets on d 1, 3, 5, and 7 after weaning at 14 d of age, as well as from piglets received oral administration of Pro and Put from 1 to 14 d old. In suckling piglets, the serum glucose, albumin and total cholesterol levels were increased (P < 0.05) with increasing age, whereas the serum globulin, urea nitrogen (BUN), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels were lowered (P < 0.05). The concentrations of most serum AA and the AA transporters related gene expressions were highest in 7-d-old piglets (P < 0.05), whereas the phosphorylation status of the mammalian target of the rapamycin (mTOR) signaling pathway in the small intestine increased in piglets from 1 to 21 d old (P < 0.05). Weaning at 14 d old increased (P < 0.05) the BUN and triglycerides levels in serum, as well as jejunal solute carrier family 7 member 6 (SLC7A6), ileal SLC36A1 and SLC1A1 mRNA abundances at d 1 or 3 post-weaning. Weaning also inhibited (P < 0.05) the phosphorylation levels of mTOR and its downstream ribosomal protein S6 kinase 1 (S6K1) and 4E-binding protein-1 (4EBP1) in the small intestine of weanling pigs. Oral administration of Put and Pro decreased (P < 0.05) serum ALP levels and increased (P < 0.05) intestinal SLC36A1 and SLC1A1 mRNA abundances and mTOR pathway phosphorylation levels in post-weaning pigs. Pro but not Put treatment enhanced (P < 0.05) serum Pro, arginine (Arg) and glutamine (Gln) concentrations of weaning-pigs. These findings indicated that early-weaning dramatically altered the biochemical blood metabolites, AA profile and intestinal mTOR pathway activity, and Pro and Put supplementations improved the AA metabolism and transportation as well as activated the intestinal mTOR pathway in weanling-pigs. Our study has an important implication for the broad application of Pro and Put in the weaning transition of piglets.     

番茄幼苗对高温时间段空气湿度控制的生理响应

为了解空气湿度对高温下番茄幼苗的生理影响，试验设计制作了智能控制自然光照生长箱，在夏季高温时段（10:00-16:00）设置了3种湿度处理，即空气相对湿度55%±5%（M处理）、70%±5%（H处理）和以不加湿作为对照（L处理）。结果表明，在平均温度为33 ℃的高温条件下，各处理番茄叶片中渗透调节物质（脯氨酸、可溶性糖、可溶性蛋白）的积累、POD活性都呈增加趋势，说明植株在不断的自我适应和调节；随处理时间延长，L处理和M处理的细胞膜相对透性增加，而H处理的细胞膜相对透性降低；而且处理期间，H处理的脯氨酸含量比L处理减少25%~70%，POD活性低14%~32%，说明植株在70%±5%的空气湿度下遭受的热胁迫较小,热害指数降低，耐热性提高。