白三叶叶片荧光特性对水分胁迫的响应

[目的]从生理角度研究白三叶(Trifolium repens)叶片叶绿素荧光参数对水分胁迫的响应.[方法]以白三叶品种"海发"为供试材料,设置75%(无胁迫,CK)、50%(轻度胁迫,LD)和25%(重度胁迫,HD)3个土壤含水量水平对植株进行培养,测定水分胁迫对一系列叶绿素荧光参数的影响,并进行统计学分析.[结果]土壤相对含水量为75%和50%时,白三叶叶片叶绿素荧光参数受到的影响不大,说明白三叶在这2种水分条件下能够正常生长;土壤相对含水量为25%时,初始荧光后极显著高于CK和LD处理,原初光能转化效率(Fv/Fm)、PS Ⅱ电子传递量子产量(φPS Ⅱ)和光化学猝灭系数显著降低.[结论]白三叶在重度干旱(HD)条件下,生理机能遭到破坏,不能正常生长,表现出旱害症状.     

芦荟原生质体融合的研究

以芦荟叶片为试材,采用酶解方法进行原生质体分离,并在此基础上对斑纹芦荟和不夜城芦荟进行原生质体融合。结果表明,以芦荟的叶肉细胞为试材,可成功分离出原生质体,而且活力较高,达90%以上。聚乙二醇（PEG）融合的结果可获得部分融合体。芦荟原生质体的成功分离主要取决于材料的来源、酶液的组成,另外还受酶解液的渗透压、温度和pH值等影响。融合的效率主要受融合剂的浓度、原生质体的生理状态及处理的时间等影响。     

几种微量元素作用及对水稻发育的影响

硅、锌、锰、硼、硒是植物生长发育中不可缺少的微量元素,植物将土壤中的微量元素转化成有机物,直接影响到人类的健康。大量试验结果证明,适量施用微肥可以明显提高水稻产量,改善水稻品质,增强水稻抗逆性和抗病性。我国在微肥方面的研究也取得较大成就。     

鬼针草90%醇提物对U14荷瘤小鼠的抑瘤效应

以U14细胞株接种小鼠制成荷瘤模型,研究鬼针草90%醇提物对荷瘤小鼠的抑瘤效应.结果表明,90%鬼针草醇提物通过提高机体免疫力抑制小鼠肿瘤生长.     

白刺属植物研究综述

从白刺属植物的分类学、花粉形态特征、生物生态学特性、化学成分及开发利用价值等方面对白刺属植物的研究现状进行了综述,其研究结果对该属植物的系统演化及分类提供了一定的依据;同时,为白刺属植物资源当前面临的问题提出了有效的解决措施.     

Is partial root-zone drying an effective irrigation technique to improve water use efficiency and fruit quality in field-grown wine grapes under semiarid conditions?

We investigated the effects of partial root-zone drying (PRD) applied at different periods on leaf water relations, vegetative development, fruit yield, must and wine quality in wine grapes (Vitis vinifera L. cv. Monastrell) during a 3-year field experiment in order to determine the importance of the timing of PRD application on physiological and agronomical vine response under semiarid conditions. Two irrigation treatments were applied: conventional drip irrigation (CI) and PRD. Both treatments received the same annual water quantity. Each year the PRD treatment was applied at different periods of the growth cycle. In 1999 PRD was applied from veraison to harvest (end July–early September); in 2000 from fruit set to harvest (mid June–early September); and in 2001 PRD from budburst to harvest (mid April–early September). Leaf water relations and gas exchange during the experimental period were not significantly affected by PRD treatment. In 1999 and 2000 there was no significant treatment effect on vegetative development, yield or fruit quality. However, in 2001 (when PRD was applied from budburst to harvest), reproductive and vegetative development was clearly altered in PRD vines. Fruit set percentage and vegetative development (shoot length, pruning weight and primary and lateral leaf area) were significantly increased in PRD vines compared to CI. This resulted in both higher yield (kg per vine) (43%) and water use efficiency (40%) compared to CI vines. Berry number per cluster and cluster weight were also significantly increased in PRD vines. Notwithstanding higher yield in PRD vines and a similar berry size, the must and wine quality was not significantly altered, indicating a higher synthesis and accumulation of photoassimilates and metabolites in the berries of PRD vines. We conclude that there was an positive effect on vegetative and reproductive growth when long-term PRD was applied from the beginning of growing season (budburst), suggesting that early onset of PRD is desirable to intensify PRD response under these semiarid conditions. Nevertheless from these results we need to further investigate the long- and short-term effects of PRD, with moderate water amounts, on vegetative and reproductive development such as flowering and fruit set processes in wine grapes.     

高粱幼叶细胞悬浮系的建立

以高粱无菌苗幼叶为试验材料,对颗粒状胚性愈伤组织的获得、细胞悬浮系的建立及影响悬浮细胞生长的主要因素进行了研究。结果表明：幼叶在MS（Murashige and Skoog）+2mg/L 2,4-D培养基上诱导出的愈伤组织,经2~3次继代筛选后获得了浅黄色、颗粒状胚性愈伤组织;胚性愈伤组织接种于液体培养基中,于25±1℃、黑暗条件下,经45~60d的悬浮震荡培养建立了高质量的细胞悬浮系,细胞生长曲线呈“S”型,细胞密度可达6.45×10 ⁵~5.08×10 ⁶个/mL以上,活细胞率可达72.76%,近圆细胞率可达87.50%;培养基的基本成分、激素种类和水平对悬浮细胞生长状态有很大的影响,相比1/2MS培养基,MS培养基为适宜的培养基,2,4-D对保持细胞系的稳定增殖至关重要,适宜的浓度为1mg/L;培养液中加入0.5mg/L KT或6-BA会造成悬浮液褐化,影响悬浮细胞的生长;最适宜的细胞悬浮培养基为L2培养基（MS+1mg/L 2,4-D,30g/L蔗糖,pH5.8）,震荡培养转速为110~120r/min,继代周期为7d,新旧培养基的接种比例为2∶1。     

大田遮阴对夏玉米淀粉合成关键酶活性的影响

在大田条件下, 以农大108为试验材料, 采用透光率为50%的遮阴网, 于苗期、穗期和花粒期3个时期分别全天遮阴处理24、28和48 d, 于处理后每隔10 d测定一次淀粉合成关键酶的活性, 并于成熟后测产。结果表明, 遮阴显著降低玉米的生物产量和籽粒产量, 苗期、穗期和花粒期遮阴处理单株生物产量分别较对照(自然光照)降低23.9%、31.4%和38.9%, 籽粒产量分别降低24.6%、35.6%和68.2%。遮阴处理显著降低了籽粒淀粉合成关键酶的活性, 叶片的磷酸蔗糖合成酶(SPS)和籽粒的蔗糖合成酶(SS)、可溶性淀粉合成酶(SSS)和淀粉粒结合淀粉合成酶(GBSS)、腺苷二磷酸葡萄糖焦磷酸化酶(ADPGPPase)、尿苷二磷酸葡萄糖焦磷酸化酶(UDPGPPase)活性都显著降低, 但花粒期遮阴影响最显著, 穗期其次, 苗期遮阴影响相对较小。认为大田遮阴使玉米产量和淀粉含量降低, 是由于光合下降, 生物产量降低以及玉米淀粉合成关键酶活性降低, 减少了光合产物向籽粒的运转和分配。     

紫花苜蓿在塔里木河流域的抗寒性研究

对21个引入的国内外紫花苜蓿(MedicagosativaL.)品种进行了抗寒性研究,结果表明,各品种在同一自然条件下,抗寒性指标含量存在差异。与对照品种新疆大叶比较,引进品种中,飞马、驯鹿、牧歌401、阿尔冈金(内)、皇冠、苜蓿王、WL-323、甘农3号、德宝、甘农2号、草原2号和德福在塔里木河流域的抗寒性较强。     

能源植物曼陀罗耐盐性的初步研究

对不同盐胁迫下(σ为0、1、2、3、4、5和6 S/m)曼陀罗的种子萌发、植株生长及叶绿素含量、气体交换参数等生长生理指标进行研究。结果表明,σ为0~3 S/m处理下,曼陀罗可正常萌发、生长与结实,σ=4 S/m时,可正常萌发、生长但不能结实,σ>4 S/m时,不能萌发;与σ=0 S/m比较,σ≥2 S/m时鲜干质量下降明显(P<0.01),但σ=1 S/m时有一定的促进作用,说明盐胁迫增强可明显抑制曼陀罗鲜干质量的增加;随盐胁迫强度增加,净光合速率、蒸腾速率、气孔导度呈上升趋势,σ=1 S/m时上升不明显,σ>1 S/m时显著上升,叶绿素含量、胞间CO2体积分数呈先上升后下降趋势。说明发芽势、鲜干质量、叶绿素含量和净光合速率、蒸腾速率、气孔导度和胞间CO2体积分数可作为曼陀罗耐盐性鉴定的重要指标。