红鳞蒲桃苗木生长和生理生化特征对不同盐分和干旱胁迫的响应

以1年生红鳞蒲桃盆栽苗木为研究对象,设置不同盐胁迫浓度及干旱程度,研究盐旱交互作用对红鳞蒲桃苗木的高、地径生长和各项生理指标的影响。结果表明：干旱和盐胁迫都抑制了红鳞蒲桃的生长,盐胁迫的影响要大于干旱胁迫,高生长受到的限制大于地径生长,2 g/kg盐分浓度在水分充足条件下促进了地径生长。相对电导率和丙二醛含量均随着干旱和盐胁迫的增强而增大。不同盐分浓度下,干旱胁迫对相对电导率的影响趋势一致,不同盐分胁迫的影响差异不显著。高盐浓度下丙二醛含量的增加显著大于低盐浓度,表明盐胁迫对红鳞蒲桃的伤害更大;红鳞蒲桃的渗透调节物质在干旱和盐交互胁迫下有一定程度的提高。水分充足时,盐分浓度的变化没有对红鳞蒲桃的游离脯氨酸含量产生影响。随着胁迫的增加,渗透调节能力显著提高。低盐浓度下,抗氧化酶活性在水分充足时没有受到显著影响,高盐浓度下,随着干旱胁迫的加剧则显著提高。     

我国粉虱类害虫的为害情况综述

对近20年来我国粉虱为害记录进行了整理,发现自2000年以来我国粉虱类害虫为害明显加重。柑橘粉虱和烟粉虱是为害最重的粉虱类群,受害最严重的省份是福建和湖南。根据各类粉虱的生物学特性,预计了未来10年我国粉虱的为害趋势,特别要警惕柑橘粉虱可能在南方柑橘产区暴发为害。     

复盐胁迫对几种燕麦种子萌发指数的影响

采用加拿大7种燕麦(A.nuda)种子,在不同梯度的Na2SO4、NaCl等组分盐溶液中进行发芽试验.结果表明:复盐胁迫下,种子开始发芽的时间推迟,发芽过程延长,随着盐胁迫浓度的增加,7种燕麦种子的发芽率、发芽势和发芽指数、简易活力指数均有不同程度的降低,而盐害指数升高,且不同品种间存在显著或极显著差异;随复盐浓度的增...     

盐渍地区草坪草品种及其混播组合筛选的研究

对 11种草坪草室内发芽试验表明 :盐浓度 0 %～ 1.6 %NaCl胁迫下相对发芽率均随盐浓度升高而下降 ,呈线性回归关系。在北方盐渍地上 0～ 2 0cm土层全盐含量不超过 1.0 %时 ,混播优于单播。表现较好的混播是多年生黑麦草 +碱茅 +草地早熟禾或匍匐翦股颖。其中多年生黑麦草发芽快、幼苗生长迅速 ,很快覆盖地面 ,有利于其他种子的萌发 ,称为保护种。碱茅幼苗期及成株后耐盐性均较强 ,但苗期生长慢 ,适宜与多年生黑麦草伴生。草地早熟禾和翦股颖品种中耐盐性较强的可作为主要草种     

高原鼠兔的精确性可持续控制技术研究——-几种杀鼠剂的对比试验

 于２００７年４－５月份在甘肃肃南县对防治高原鼠兔精确用药进行试验,将５种常见杀鼠剂的推荐用药浓度、用药量按等比级数增、减剂量进行插组,作正交对比试验,结果表明,推荐用药浓度、用药量和饵料种类与调整后的用药浓度、用药量和饵料种类对高原鼠兔的灭洞率有一定的差异性。影响灭洞率的主、次因子顺序是：杀鼠剂＞用药浓度＞投饵量＞饵料种类。以防效为评价指标,５种参试杀鼠剂的排序为：大隆（８３．９％）＞Ｄ 型肉毒梭菌生物毒素（８２．６％）＞溴敌隆（７９．４％）＞Ｃ 型肉毒梭菌生物毒素（７５．０％）＞ 敌鼠钠盐（６８．９％）。最佳处理组合是：１）用０．１５％的Ｄ 型肉毒梭菌生物毒素、小麦饵料、２５ 粒投饵量;２）０．０１％ 大隆、青稞饵料、５ｇ投饵量;３）０．０１％ 溴敌隆、小麦饵料、３ｇ投饵量。     

飞机草的危害及防治措施简介

飞机草Eupatorium odoratum是一种有毒、侵占性极强的检疫性杂草,广泛分布于南美洲、亚洲、非洲、澳洲30多个国家的热带地区,目前已侵入我国南方各省并肆孽成灾。它侵占林地、草场、农田,危害农、林、牧业,危及人、畜健康,严重阻碍社会经济发展。目前国内外防治措施有:机械防治、替代防治、化学防治、生物防治、综合防治等。科技工作者多年的实验表明上述防治方法有一定的效果,为飞机草的防治工作提供了可行性建议。     

不同土层加入生物质炭对盐分淋洗的影响

生物质炭作为土壤调理剂,能够显著地改良和培肥土壤,但对盐渍化土壤盐分淋洗的影响缺乏研究和了解。本研究采用土柱模拟试验,将蘑菇棒生物质炭以质量比10%,添加到内蒙古河套地区硫酸盐盐渍化土壤0~20 cm,0~35 cm和0~70 cm的土层中,并进行淋洗,测定淋出液和土壤盐分及主要盐分离子含量,以期了解生物质炭对土壤盐分和主要盐分离子洗脱的影响。结果表明:加入生物质炭的土柱,淋洗液出流的时间提前了34~37 d,电导率降低至5 m S·cm-1,需要的时间缩短了94~101 d;比起0~20 cm和0~70 cm土层加入生物质炭处理,0~35 cm土层加入生物质炭淋出液出流时间最早,盐分洗脱的效果最好。生物质炭对盐分离子淋洗也产生不同的影响,促进Na+、K+和Mg2+的洗脱,但抑制Ca2+洗脱;在淋洗初期生物质炭促进Cl-和SO42-洗脱,后期促进了HCO3-和CO32-的洗脱。可见,生物质炭可用作盐渍化土壤调理剂,不仅缩短盐分洗脱时间,而且还可以提高洗盐效率。     

硅对盐胁迫下葡萄幼苗生理效应的影响

以酿酒葡萄"赤霞殊"(Cabernet Sauvignon,CS)1年生扦插苗为试材,采用营养液水培系统,研究了根施外源硅(K2SiO3·9H2O,Si)对盐(50 mmol/L NaCl)胁迫下赤霞珠葡萄幼苗叶片生理生化特性的影响.结果表明:盐胁迫处理下,葡萄幼苗叶片超氧阴离子(O2-')产生速率加快,过氧化氢(H2O2)、丙二醛(MDA)含量和相对膜透性增加;超氧化物歧化酶(SOD),过氧化物酶(POD)和过氧化氢酶(CAT)活性增强;组织含水量降低;施用2.0mmol/L Si明显抑制了O2-、H2O2和MDA的积累,增加了组织含水量,并进一步提高了抗氧化酶SOD和POD的活性.说明外源Si可通过提高盐胁迫下葡萄幼苗体内的抗氧化酶活性,从而降低活性氧(ROS)水平,一定程度上减轻盐胁迫对植株所造成的细胞膜脂过氧化伤害,增强其耐盐性.     

Salt Separation Processes in the Saltcedar Tamarix ramosissima (Ledeb.)

Salt cedars (Tamarix) are invasive halophytic species and heavy water consumers. However, Tamarix possesses interesting characteristics accounting for its opportunistic and resilient abilities: analogous to a miniature photodesalinization machine, it thrives on saline soils toxic to most plants. Here we observe, document, and reveal the salt separation process of T. ramosissima. Specimens were cultivated under controlled artificial conditions, then analyzed by microscopic and spectroscopic techniques. Tamarix ramosissima is shown to produce varied morphologies of salt crystal aggregates from vesiculated trichomes and possess the ability to separate anions and cations. Sodium chloride, potassium chloride (KCl), and potassium sodium sulfate [K_2.25Na_1.75(SO₄)₂] were major exuded salt crystal phases, with smaller quantities of other phases present. Compositions of crystals exuded by individual plants were consistent with compositions of the soils they grew on. Although T. ramosissima may be an invasive nuisance, it may possess other worthwhile attributes such as the potential to be a viable phytoremediator and environmental indicator.     

The Comet assay for detection of DNA damage in canine sperm

Sperm DNA integrity is a fundamental prerequisite in fertilization and embryo development. Among DNA integrity tests, the Comet assay is an accurate and sensitive test for the detection of sperm oxidative damage. The aim of this work was to evaluate sperm oxidative damage using the Comet assay and to study the correlation between Comet and routine assays for the evaluation of semen quality. Dogs were divided in two groups: group A (n = 6), comprising dogs with abnormal spermiogram, that is astheno‐, terato‐ or oligoasthenoteratozoospermic (OAT); and group B (n = 8), comprising normospermic dogs. The distribution of sperm oxidative damage was significantly different between the two groups (p = .001): group A—median: 31.55%, interquartile range (IQR): 30.18–38.01; group B—median: 0.90%, IQR: 0.65–1.96. The correlation between oxidative damage and abnormal morphology was high (r = .846; p < .001). There was a negative correlation between progressive motility and oxidative damage (r = ?.792; p = .001). Basal and oxidative DNA damage of spermatozoa are increased in dogs with non‐normospermic semen. In conclusion, and considering the elevated correlation with classical tests of sperm quality, the Comet assay has ample potential for clinical and research purposes in dogs.