不同有机酸对香石竹切花保鲜效果的影响试验

以2%蔗糖溶液为对照,在对照中分剐加入50mg／L水杨酸、50mg／L苯甲酸＋50mg／L山梨酸和100mg／1．山梨酸的保鲜液保鲜香石竹鲜切花。结果表明,这5个处理都能增加花朵鲜重,促进花朵开放,增加叶片叶绿素和花瓣蛋白质含量,延长花朵寿命,提高观赏价值。含有50mg／L苯甲酸＋50mg／L山梨酸保鲜液比单独使用水杨酸和山梨酸效果好。     

The effect of cutting carnations in the bud stage on quality and yield of flowers from a nursery

The harvesting of carnation buds at early stages of development resulted in an increase of 10–60% (depending upon the growing-period and the cultivar) in the number of newly formed flower buds, even when the carnations were grown during a period of 11 months. A 22-month period of cultivation resulted in a larger increase in the number of buds.Tight buds could be successfully opened with opening-solution to fully developed flowers, without losing their quality when compared with control flowers harvested at the half-bloom stage.     

4种植物次生物质对黄粉虫生长发育的影响及维生素B1的增效作用

为了研究植物次生物质对鞘翅目昆虫生长发育的影响,为绿色防控害虫提供理论依据,本试验选取槲皮素、芦丁、京尼平、绿原酸4种植物次生物质,研究其对黄粉虫的触杀作用及生长发育的影响,并就维生素B 1对植物次生物质防御黄粉虫的增效作用进行了探索。研究结果表明,京尼平对黄粉虫生长发育的抑制作用较强,京尼平处理组黄粉虫的幼虫期显著延长,约为对照的1.3倍,幼虫活动缓慢,蛹重下降,化蛹率低且畸形蛹较多,成虫产卵量仅为对照40%。两两植物次生物质组合使用对黄粉虫的抑制作用比单独使用效果好,其中最佳组合为京尼平和槲皮素。在植物次生物质中添加0.3%的维生素B 1可以增强植物次生物质对黄粉虫的触杀效果。     

Effects of biennial cropping and controlled shoot density on yield performance and fruit quality in red raspberry (Rubus idaeus L.)

Effects of annual versus biennial cropping with varying shoot densities on plant structure, berry yield and quality were studied in ‘Glen Ample’ raspberry over a period of four seasons (two cropping years). In the vegetative phase, primocane height and internode length were larger in the annual than in the biennial cropping system. These parameters as well as Botrytis infestation increased with increasing shoot density. In both cropping years, berry yields per unit area were about 20% higher in the biennial cropping system, whereas yields per shoot were not significantly different in the two systems. In both cropping systems, yields per shoot strongly declined with increasing shoot density, while yields per metre row increased slightly. Regardless of cropping system, yields per metre row did not increase with increasing shoot density beyond eight shoots per metre. The concentrations of dry matter, soluble solids, titratable acidity and ascorbic acid as well as the intensity of juice colour all declined with increasing shoot density. We conclude that under controlled shoot density conditions, there is little scope for biennial yield increases that fully compensates for the lost crops every second year. However, the system greatly facilitates berry harvest and eases plant disease pressure.     

Endophytic bacteria associated with banana cultivars and their inoculation effect on plant growth

The occurrence and role of endophytic bacterial communities in banana under different field-grown conditions have not yet been explored. Hence, a survey was conducted in five different banana cultivars – Rasthali, Hill banana, Co1, Nattu Poovan and Red banana – for the assessment of bacterial endophytes grown in Tamil Nadu, Southern India. From 352 endophytes isolated, 17 were selected based on distinct morpho-physiological characters. The 17 selected isolates were grouped into eight different genera, which belong to the phyla Actinobacteria, Firmicutes and Proteobacteria, with remarkable differences in the bacterial compositions among the banana cultivars. Higher bacterial diversity was observed in Rasthali and Red banana when compared to Co1 and Nattu Poovan. Isolates exhibited at least one functional plant growth-promoting trait when tested for siderophore production and indole-3-acetic acid (IAA) synthesis. Representative isolates from eight different genera were further analyzed for plant–microbe interactions. A seedling inoculation experiment on tomato showed a significant effect on seed germination, seedling growth, vigor index, and biomass production compared to the uninoculated control. However, a comprehensive approach is needed to evaluate the full potential of bacterial endophytes to improve quality and yield in banana under field conditions.     

The effect of nitrogen,volume of media,plant density and module shape on the growth of asparagus seedlings

There were three experiments in which the seedlings were raised in media contained in plastic cells. In Experiment 1, 150 or 200 mg l^?1 N were applied in factorial combination with cell volumes of 20, 32 or 50 cm³, There were 6 successional harvests. All cells were 7.5 cm deep and cylindrical in shape. Experiment 2 compared these 3 cell volumes at densities of 983, 1532 or 2440 plants per m². Cell diameters restricted the 50-cm³ cell to the 983, and the 32-cm³ cell to the 983 and 1532 plants per m² densities. 200 mg l^?1 N increased shoot growth, but not root growth. This increase in shoot growth was not considered advantageous. Seedling growth increased with increases in cell volume, but there were no responses to changes in plant density. Experiment 3 compared a cell having an inverted pyramid shape with a cylinder. The cylinder, despite holding 20% less media, produced the larger seedlings.     

樱桃透光和郁闭树冠相对光照强度及其果实品质和产量的差异

 以13年生‘红灯’甜樱桃（Prunus avium L.）为试材,应用树冠分格方法,研究了树冠透光和郁闭两种冠型内相对光照强度及其果实品质和产量的差异,以及相对光照强度与果实产量品质的关系。结果表明,两种树冠内相对光照强度均自下而上逐渐增高,透光和郁闭树冠小于30%的相对光照区域分别占树冠总体积的25.23%和52.78%。透光树冠果实分布均匀,主要集中在树冠1.5～2.5 m的高度;而郁闭树冠果实分布差异较大,主要在树冠的外围和上部;产量分别是9.02t.hm-2和3.53t.hm-2。果实品质因素与相对光照强度的回归分析表明樱桃单果质量、果实硬度、果实可溶性固形物含量、可滴定酸含量、固酸比最佳的相对光照强度值分别为76.52%、46.84%、100.00%、41.63%和75.77%。     

不同枝量类型富士苹果光强分布及产量品质比较

对陇东改良纺锤形富士苹果3种枝量类型树冠内相对光照强度、树冠不同部位光照分布特征、果实产量、产量分布特征及品质进行了对比研究。结果表明:枝量过多型树冠内小于30%的相对光照强度比例最大,枝量合理型次之,枝量不足型最小。枝量合理型、枝量不足型、枝量过多型小于30%的相对光照体积所占树冠总体积分别为32.23%、24.19%、49.53%;产量分别为3 195、1 555、2 098 kg/667m2;果实品质各项指标枝量不足型略高于枝量合理型,但二者均达到了优质苹果的要求,确定出陇东地区富士苹果优质高产的最适留枝量为84 000/667m2左右。     

摘心方式对日光温室香石竹切花产量及品质的影响

在日光温室内以“恋人”、“紫罗兰”、“香妃”、“魅力”和“玛斯特”5个香石竹品种为试材,进行一次摘心、一次半摘心、二次摘心、二次半摘心4种不同摘心方式处理,测定各处理的切花产量及品质指标.结果表明:随摘心次数的增加,分枝数增加,切花量上升,但切花率下降,花茎变短,花径变小,切花品质下降.摘心方式对不同品种的分枝数、切花量度品质的影响不一致.一次半摘心处理,切花量及切花率较高且品质优良,为多数切花品种的最佳摘心方式.     

Effect of CO2 enrichment on photosynthesis,growth and yield of tomato

Net photosynthesis of tomato plants was measured as CO₂ uptake in various light intensities, CO₂ concentrations, O₂ concentrations and temperatures during short-term experiments. Net photosynthesis increased significantly with increasing CO₂ concentration at all light intensities, even at the lowest one. The optimal temperature for photosynthesis increased with CO₂ enrichment. The changes in photosynthesis when the $\text{CO}{}_2\text{O}{}_2$ ratio was varied suggest that the effect of CO₂ enrichment is a result of a reduction in photorespiration.To determine whether the increase in photosynthesis caused by CO₂ enrichment would produce a greater yield, tomato plants were cultivated from seed to harvest in a tightly-closed greenhouse that was enriched with CO₂ continuously during the entire growing-period. The control greenhouse was ventilated by openings in the roof and door. The temperature of the 2 greenhouses was kept the same. Plants enriched with CO₂ showed a significant increase in fresh and dry weight and yield of tomatoes. The results are discussed in relation to earlier work in which CO₂ enrichment was discontinued when there was a need for ventilation.     

The effect of breeding-habitat patch size on bird population density

An individual-based simulation model was used to study the effect of the relative location of food and nest sites in the landscape on the relationship between the breeding habitat patch size and bird population density. The model predicted that when both food and nest sites are located exclusively in the breeding habitat patches, larger patches tend to harbor higher population densities. But when food starts to be added to the `matrix' habitat and taken out of the breeding habitat the advantageous effect of larger patches diminishes and eventually the trend reverses, with small patches having higher population densities. This pattern arises from the combined effect of the existence of an extended foraging area around patches and an intrinsic advantage of large habitat patches associated with the concentration of food resources and potential colonizers. The effects of interspecific interactions and the management implications of the model are discussed.     

The effect of ethephon on the growth and development of Liatris spicata

Summary

The first experiment studied the effect of applying ethylene biosynthesis regulating compounds (ethephon 1000 ppm, silver thiosulphate 0.4 mM and cobalt chloride 5 mM) on the growth and development of Liatris spicata cv. Callilepis. The results pointed to the important growth retardant properties of ethephon and the increased number of flowering stems per corm which could be obtained by pre-planting application. A second experiment aimed to optimize ethephon treatment in Liatris by applying the growth retardant in different concentrations (100, 700, 1300, 1900 and 2500 ppm) at three stages of development: stage I (pre-planting), stage II (immediately after the formation of basal leaf rosette) and stage III (when the main shoot began its rapid longitudinal growth). Besides confirming the effects produced by ethephon in the first experiment, the results suggested that the application of high ethephon concentrations (1900 and 2500 ppm) during stage II of growth produced many miniature flowering stems coming from the principal or secondary shoot.     

苗床覆盖和播种密度对福建山樱花苗木生长的影响

采用苗床不同覆盖方式和不同播种密度进行福建山樱花播种育苗效果比较试验。结果表明：以塑料小拱棚＋碎草覆盖苗床的发芽率最高,达88.5%;苗木密度以株行距10 cm×10 cm的生长量最大,平均苗高为153.7 cm,平均地径为0.82 cm,平均主根长度为30.4cm,≥5 cm长Ⅰ级侧根平均条数为11.0条。     

不同种植密度对藏木香产量和品质的影响

以产量、灰分含量、土木香内酯含量为标准,研究了不同种植密度对藏木香产量和品质的影响,以期为匙叶翼首草的人工栽培提供理论依据和技术指导。结果表明:藏木香在田间生产中种植密度为40 cm×40 cm时,其产量和土木香内酯含量均最高、品质最优,建议在生产中大力推广。     

植物生长调节剂对紫果西番莲离体培养的影响

以紫果西番莲的茎段为外植体，以1／2MS为基础培养基，添加ZEA2－3mg/l，外植体萌芽率高达100％。不定芽在1／2MS培养基中，附加B A1.0 NAA0.1mg/l，其增殖系数最高。芽苗不定根的诱导培养基1／2MS＋IBA1.5-2.3mg/l，其生根率较高，当IBA为2.5mg/l时芽苗生根率达100％。     

蔷薇科12属代表植物叶片气孔密度研究

该文研究了蔷薇科12属代表植物的叶片气孔密度和同属异种植物的气孔密度;同属同种植物在不同生境下的气孔密度.结果得知:蔷薇科12属代表植物属与属之间气孔密度多数相同,个别的存在差异;气孔密度的大小与植株的着生位置、叶片的着生位置及生境均有一定的关系;同属植物在相同的条件下气孔密度相近,但在不同的条件下气孔密度差异很大.同时还得知:在干旱条件下生长的植物,叶片的基部和中部气孔密度大;在水肥条件好的情况下叶片的尖端气孔密度大.     

The effect of quantum flux density and net photosynthetic rate on morphology and time to flower of hybrid geraniums

Three cultivars of 63-day-old hybrid geraniums (Pelargonium × hortorum Bailey) were grown under high (800–1200 mE m^?2 s^?1), medium (300–600 mE m^?2 s^?1) or low (100–160 mE m^?2 s^?1) quantum flux densities. Plants grown under low light and 25% greater total leaf area but 25% lower dry weight than plants grown under medium or high levels, regardless of cultivar. Time to flower in all cultivars was negatively correlated with quantum flux density, and specific leaf weight and leaf thickness were positively correlated to net photosynthetic rate. ‘Sprinter Scarlet’ and ‘Sooner Red’ had similar correlation coefficients (r) for most relationships, but r values for ‘Ringo’ were generally not as strong. Quantum flux density appears to affect both organogenesis and maturation of the flower.     

种植密度对辣椒DU01光合特性及产量的影响

以适于一次性采收的辣椒新品种DU01为试验材料,设置5个种植密度,对DU01的光合特性及产量构成因素等进行研究.结果表明,盛果期后,DU01的叶面积、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)随着密度的增加而降低,叶绿素a(Chla)、叶绿素b(Chlb)、类胡萝卜(Car)和总叶绿素(Chlt)含量随...     

五味子不同采光结构光照强度及利用率的研究

通过测定五味子各种采光结构表面的光照强度和单位土地面积光利用率的日变化和月变化,以确定五味子生产的合理采光结构,提高产量。结果表明:不同采光结构平均光照强度顺序为:30°斜架(64.2 klx)45°斜架(53.8 klx)南北架(49.5 klx)东西架(38.8 klx),30°斜架的光照强度分别比南北架高29.7%,比东西架高65.5%;光利用率的顺序为:斜架(100%)南北架(39.3%)东西架(24.3%),斜架的光利用率分别是南北架的2.5倍,东西架的4.0倍。栽培五味子宜采用斜架。     

种植密度对不结球白菜叶面积指数动态变化及产量的影响

以不结球白菜"春油5号"为试材,设置不同种植密度(667m^2种植13 340、16 675、17 787、22 233株),研究了不同种植密度对不结球白菜叶面积指数动态变化及产量的影响,以期为不结球白菜的合理密植提供参考依据。结果表明:在整个生长季节供试的不同种植密度不结球白菜的叶面积指数、单株质量及产量的发展均呈"S"型变化,播种后41d各指标缓慢增加;播种后41～54d各指标呈指数型增长,各种植密度间差异显著;后期到达最高点后保持不变甚至出现下降,处理间差异消失。相关分析表明,种植密度与叶面积指数和产量呈正相关,与单株质量呈负相关,综合不结球白菜单株质量、产量考虑,适宜栽培株行距为20cm×20cm(667m^2种植16 675株),适宜的叶面积指数为3。