不同光质对豇豆幼苗光合特性和若干生理生化指标的影响

在南方设施栽培环境条件下,以矮生豇豆为试材,研究不同光质(红光、蓝光、绿光、白光)对叶片光合特性及生理生化指标的影响.结果表明,红光处理有利于叶绿素含量、光合速率、蒸腾速率、可溶性糖含量的提高,而蓝光处理则有利于类胡萝卜素含量、可溶性蛋白质含量的提高.不同光质处理豇豆叶片的超氧化物歧化酶、过氧化物酶、过氧化氢酶活性均呈...     

不同架式对设施葡萄光合特性及果实品质的影响

以设施红提葡萄为试材,研究不同的整形方式对葡萄叶片光合特性和光合关键酶活性的影响。结果表明:与扇形整形方式相比,L形和FI形整形方式可明显提高叶面积;在果实迅速发育时期,L形整形方式显著提高了叶绿素含量,Rubisco及Rubisco活化酶活性显著升高;同时,叶片质膜ATPase和叶绿体膜ATPase活性也显著升高,从而提高了叶片的光合速率。L形、FI形和V形整形方式均不同程度提高了平均单果质量、可溶性固形物含量,降低了可滴定酸含量,而L形则显著地提高了果实的品质。因此,适当的整形方式可通过调节提高设施葡萄的叶绿含量、光合关键酶和ATPase活性来提高光合速率,最终提高果实的品质。     

Interrelations of organism prevalence, specimen collection method, and host age, sex, and breed among 8,354 canine urinary tract infections (1969-1995)

Selected information was compiled from canine urinalyses and urine cultures conducted between January 1969 and December 1995. Eight thousand three hundred fifty-four microbial isolates (bacteria and fungi) included 4,873 isolates from females and 3,481 from males. Ten bacterial genera accounted for 96.3% of the urinary isolates, including Escherichia coli (44.1%), Staphylococcus spp. (11.6%), Proteus spp. (9.3%), Klebsiella spp. (9.1%), Enterococcus spp. (8.0%), and Streptococcus spp. (5.4%) as the 6 most common isolates in both genders of dogs. Among these 6 genera, female dogs were generally predisposed over males, although males had more urinary tract infections (UTIs) caused by Klebsiella spp. Distributions of ages at UTI diagnosis tended to be similar between genders. Infection with a single microbial species was responsible for >72% of UTIs in both genders. Among females, 40 breeds and a mixed-breed group represented 90.2% of all positive urine cultures, 88.4% of the individual dogs with UTIs. and 88.2% of the microbial isolations. Among males, these same 41 breed groups represented 87.9% of all positive urine cultures, 87.6% of the individual dogs, and 88.2% of the microbial isolations.     

江南地区大棚促成—避雨栽培下葡萄品种光合特性的比较

 研究表明, 促成—避雨栽培( Forcing-cultivation and Rain-shelter-cultivation, F-C & R-S-C) 条件下7个葡萄品种: ①净光合速率( Pn) 日均值、光饱和点(LSP) 、光补偿点(LCP) 在促成阶段分别为CO₂ (5.74 ±4.33) ～ (7.87 ±5.85) 、494～1 110和9.6～5.15 μmol·m^-2 ·s^-1 , 在避雨阶段分别为(3.85±1.82) ～ (5.62 ±3.23) 、806～1 407和16.5～33.5 μmol·m ^{- 2} ·s^{- 1} ; 各品种的CO₂ 饱和点(CSP) 、CO₂补偿点(CCP) 在促成阶段分别为717～1 500和60.6～88.0 μL·L ^{- 1} , 在避雨阶段分别为944～1 601和14.1～59.1 μL·L ^{- 1} ; ②在促成阶段的Pn日均值、Pn日高峰值、Pn日积分值、气孔导度( Gs) 、蒸腾速率( Tr) 、LSP和CSP相对于避雨阶段较高, 光合表观量子效率(AQY) 、羧化效率(CE) 、LCP、CCP和多数品种的水分利用效率(WUE) 则较低; ③上述指标在不同栽培阶段各品种间的差异显著, 其中‘黎明无核’、‘里扎马特’和‘郑州早玉’的Pn日均值、WUE、AQY、CE、LSP和CSP均相对较高, 而LCP和CCP相对较低, 较适宜该种设施栽培。     

水分对有机基质栽培番茄生长、生理特性和产量的影响

以番茄品种齐粉为试材,研究了基质相对含水量为(95±5)%、(80±5)%、(65±5)%和(50±5)%4个处理对有机基质栽培番茄生长、生理特性和产量的影响。结果表明,随着基质相对含水量的升高,有机基质栽培番茄的株高、茎粗、叶面积、节间长和产量均明显增加;番茄叶片的净光合速率、蒸腾速率、气孔导度都增大,而水分利用率下降。基质相对含水量为80%的处理与相对含水量为50%和65%的处理相比,番茄长势较好,蒸腾强度、光合强度和产量较高。基质相对含水量为95%的处理与80%的处理相比,产量未有显著增加,且植株有徒长现象,水分利用率低,水资源浪费严重。     

不同浓度CO2对黄瓜光合速率的影响

研究了CO2浓度在200、350、500、700、1 000 mg/kg处理下的黄瓜叶片的光合速率.结果表明:增加CO2浓度,可显著提高黄瓜叶片的光合速率,在强光下,效果尤其明显.黄瓜叶片光合速率对不同CO2浓度的响应都有一个由低到高再低的趋势.空气CO2浓度,细胞间隙CO2浓度与光合速率是一致的,在高CO2浓度下,气孔导度一般不是光合速率的限制因子.     

日光温室牡丹花石榴光合特性研究

以LI-6400光合作用测定系统对日光温室牡丹花石榴的光合特性进行测定。结果表明,在晴天条件下,牡丹花石榴光合速率日变化呈双峰曲线,最高峰在8时,次峰在15时,中午有明显的“午休”现象。光合作用的光补偿点和饱和点分别为32μmol/m2/s和1200μmol/m2/s,CO2补偿点和饱和点分别为16μmol/mol和850μmol/mol。     

龙眼光合作用对环境温度的响应和适应

在年生长期中测定了龙眼叶片光合作用对测度的影响,结果发现,龙眼光合作用最适温与最适温下的光饱和光合速率都有一定的季节变化,但季节变幅不大,不同季节的光合最适温在２２～２８℃之间,光合最适温与植株前５－１０天所处的环境平均气温密切相关,春秋季光合最适明显高于环境气温,夏季光合最适明显低于环境气温,光合最适温随光照强度的变化而变化,这些结果显示了龙眼光合作用对环境温度的特殊要求。     

唐菖蒲不同品种生理特性及栽培适应性的研究

１９９３～１９９７年研究表明,在贵阳地区,适应性较强的唐菖蒲浅色花品种的休眠球茎、发芽种球、幼苗期球茎及幼苗根的超氧化物歧化酶活性高于适应性较弱的深色花品种,而深色花品种的开花期母球、新球、新根、茎、叶、花药的蛋白质含量以及上部叶片的光饱和点、净光合速率、光呼吸速率、暗呼吸速率高于浅色花品种,花瓣的蛋白质含量低于浅色花品种。由此推测,唐菖蒲不同品种的栽培适应性差异与以上生理生化性状差异有关。     

Influence of Seed Treatment with Uniconazole Powder on Soybean Growth,Photosynthesis, Dry Matter Accumulation after Flowering and Yield in Relay Strip Intercropping System

Abstract

The relay strip intercropping system of wheat-corn-soybean is widely used in southwest China. However, it is hard to produce soybean stably with this system, since the growth of soybean plants is slower under shading by corn at the seedling stage, and it is compensated by accelerated growth after the symbiotic stage. Soybean plants show excessive vegetative growth due to more rain during the flowering stage, which results in fallen petals, fallen pods and lower yield. This study investigated whether seed treatment with uniconazole powder (0, 2, 4 and 8 mg kg^–1 seed) suppresses excessive vegetative growth of soybean plants during the flowering stage and delays senescence of photosynthetically active leaves at the pod-setting stage. If such events are correlated with changes in photosynthesis, they may affect dry matter accumulation and seed yield in the relay stripping system. Uniconazole promoted biomass accumulation from 31 (R₃) to 61 (R₅) days after flowering (DAF) and seed yield. Seed treatment with uniconazole raised the net photosynthetic rate, stomatal conductance, transpiration rate, and total chlorophyll and chlorophyll a contents. In contrast, uniconazole reduced leaf area index (LAI) from 1 DAF (R₁) to 46 DAF (R₄) with the increase in uniconazole concentration, whereas, uniconazole significantly increased LAI at 61 DAF, and the greatest promotion occurred at 2 mg kg^–1 treatment. The study clearly showed that uniconazole effectively suppressed excessive vegetative growth of soybean during flowering stage, delayed senescence of photosynthetically active leaves at pod-setting stage and induced higher yield, which were related to the changes in photosynthetic rate, chlorophyll content, dry matter accumulation and LAI in the relay strip intercropping system.