崖豆藤育苗技术

经过正交试验设计研究不同扦插基质、促根剂及浓度时崖豆藤生根情况的影响.结果表明,扦插基质和促根剂对生根均有一定影响,促根荆浓度500×10-6和1 000×10-6的差异不显著,各因素最佳组合是以黄壤为基质、生根粉6号为促根剂、浓度500×10-6.并探索了不同扦插时间对生根的影响,6月及9月份的生根成活率较低.处理2最高也才迭34%,最低为15%,在3月、4月、5月、10月份生根率差异不大,处理9差异最高,为10%,处理4差异最低,为1%.     

岩白菜幼叶总RNA的提取方法研究

为了筛选出提取岩白菜幼叶总RNA的最佳方法,为岩白菜的转录组测序提供技术支撑,本文采用6种试剂盒法提取岩白菜幼叶的总RNA,通过凝胶电泳和BIO-RAD核酸蛋白检测仪检测提取的RNA样品的质量和纯度,并对提取效果进行了分析.结果表明:用Trizol Kit、Trizol A+ Kit、Transzol Up Kit提取的幼叶总RNA没有28S rRNA和18S rRNA条带;用inunPREP Plant RNA Kit提取的RNA具有28S rRNA和18S rRNA条带,但条带模糊、含量低;用Transzol Plant Kit和EasyPure Plant RNA Kit提取的RNA具有28S rRNA和18S rRNA这2条清晰的条带,但后者提取的总RNA的得率和纯度更高.综合考虑后认为EasyPure Plant RNA Kit法是快速提取岩白菜幼叶总RNA的最佳方法.     

芥菜提取物对西瓜枯萎病菌的抑菌活性及抑菌谱测定

研究芥菜提取物的抑菌活性,为开发芥菜作为杀菌剂应用于农业生产奠定基础,为芥菜资源的合理利用提供理论依据。采用菌丝生长速率法,测定芥菜提取物对西瓜枯萎病菌、水稻纹枯病菌、葡萄座腔菌和烟草黑胫菌等植物病原菌菌丝生长的抑制作用。结果表明:采用不同有机溶剂获得的芥菜提取物对西瓜枯萎病均有一定抑制作用,以95%乙醇提取的抑菌效果最好,其提取物的抑菌率可达90%以上。最小抑菌浓度(MIC)和最小杀菌浓度(MFC)分别为0.5、1.0 g/mL,通过毒力方程的测定,它的半抑菌浓度(EC₅₀)为0.2212 g/mL。通过试验对其他10种植物病原菌的抑菌活性表明:芥菜乙醇提取物对水稻纹枯菌、葡萄座腔菌、烟草黑胫菌、辣椒菌核病菌等4种病原菌的抑菌效果较强,其EC₅₀分别为0.0898、0.1265、0.1679、0.1685 g/mL,对葡萄炭疽病菌的抑制效果最弱,EC₅₀为0.5833 g/mL。芥菜提取物具有很强的抑菌活性,并且具有较广的杀菌谱,值得进一步深入研究。     

南岭发现金斑喙凤蝶2个新寄主

2009年6月和8月在对南岭国家级自然保护区的蝴蝶区系调查中发现,金斑喙凤蝶在金叶含笑和乳源木莲上产卵,卵孵化后取食其嫩叶,确定此2种植物是金斑喙凤蝶的寄主植物,有可能还是该蝶的嗜食性寄主植物。此发现有助于开展金斑喙凤蝶保护生物学研究,有着重要的生态意义和科学价值。     

柚芽变株系类胡萝卜素代谢差异基因的转录组学分析

为了研究‘琯溪蜜柚’果实红肉突变株系类胡萝卜素代谢和芽变的分子机制,本研究以‘琯溪蜜柚’及其芽变一代品种‘红肉蜜柚’和芽变二代品种‘三红蜜柚’果实为材料,使用RNA-seq技术研究3个品种3个发育时期果肉类胡萝卜素的代谢。经生物信息学分析,共筛选出参与类胡萝卜素生物合成显著差异表达的10个基因,分别为八氢番茄红素合成酶基因（PSY）、六氢番茄红素脱氢酶基因（ZDS）、类胡萝卜素异构酶基因（CRTISO1、CRTISO2）、紫黄质脱环氧酶基因（NPQ1）、9-顺式-环氧类胡萝卜素双加氧酶基因（NCED3、NCED5）、脱落醛氧化酶基因（AAO3）、ABA 8’-羟化酶基因（CYP707A1）、类胡萝卜素裂解双加氧酶基因（CCD4）。共表达分析揭示了7个家族转录因子的表达模式与类胡萝卜素合成基因高度相关,分别为MADS、bZIP、bHLH、MYB、AP2/ERF、NAC和WRKY。通过实时荧光定量PCR（qRT-PCR）验证了部分基因的表达模式,结果与RNA-seq结果高度一致。此外,经对‘红肉蜜柚’果肉转色期的初生和次生代谢通路DEGs富集分析,发现类胡萝卜素的积累过程中,细胞壁、脂质、类黄酮代谢差异基因大量富集。研究结果揭示,‘琯溪蜜柚’果实红肉突变品种‘红肉蜜柚’和‘三红蜜柚’果实类胡萝卜素的形成和积累,是由类胡萝卜素的代谢相关酶基因差异表达和转录因子调控引起的;在果肉红色芽变的同时,伴随着与汁胞粒化相关的基因突变。这对进一步开展柚子果实类胡萝卜素的形成与积累、汁胞粒化研究,为解析柚果实不同颜色突变、汁胞粒化的机制有重要参考价值。     

佯黄竹优良无性系选育

以丛生竹新品种佯黄竹（Bambusa changningensis Yi et B.X.Li）为选育对象，以竹材产量高、浆（材）用品质好为选育目标，对佯黄竹4个无性系进行对比试验。结果显示：无性系YHZ03各项指标表现较好，栽植后3年即可正常投产，单株平均发笋量为5.4株，新生竹平均胸径6.50 cm、平均秆高13.20 m、平均秆质量8.60 kg/株；制浆造纸性能优于当地其他竹种，且具有区域适应性强、性状稳定、抗寒性较强等特点，在川南海拔1 000 m以下地区适宜推广种植。     

Simulation of effects of soil bulk density and p addition on k uptake by soybeans

Abstract

Increasing soil bulk density has been shown to reduce root growth and decrease K uptake by soybeans (Glycine max L. Merrill). Changing soil bulk density also affects soil buffer power, b, and effective diffusion coefficient, De, which affect K influx. The relative decrease in K uptake due to reduced root growth as compared to reduced K influx is not known. Addition of P may affect root growth and P influx properties of plant roots. The objectives of this paper were (1) to use the Cushman mechanistic model to simulate the effect of changing soil bulk density and soil P on K uptake by soybeans, and (2) to determine the parameters that are changed by changes in bulk density and added P and their effect on K uptake. Plant and soil data of an experiment where Williams soybeans were grown for 21 days in pots of Raub (Aquic Argiudoll) silt loam with factorial treatments of two rates of K (0 and 100 mg K kg^‐1 soil), two rates of P (0 and 100 mg P kg^‐1 soil), and two bulk densities (1.25 and 1.45 g cm^‐3 ) were used to verify the model. Plant and soil parameters for the model were measured independently of the verification experiment. Predicted K (y) uptake agreed with observed uptake (x) (y = 1.09x‐0.19; r = 0.97) for the P x K factorial and (y = 1.19X‐0.22; r = 0.90) for the K x soil bulk density factorial treatments. In a sensitivity analysis, the model predicted a maximal K influx at a soil bulk density of 1.38 g cm^‐3. The greatest effect of soil bulk density on K uptake was due to reduction of root growth. Increased K uptake as a result of P addition was because of the effect on root growth.     

Overcoming the Stressful Effects of Salinity and Acidity on Soybean Nodulation and Yields Using Signal Molecule Genistein Under Field Conditions

Soil stresses such as salinity and acidity may adversely affect nitrogen (N)₂-fixation. The hypothesis of this study is that soil salinity and acidity inhibit soybean [Glycine max (L.) Merr.] nodulation and N₂-fixation due to, at least in part, disruption of the signal exchange process. The objectives were: 1) to determine the effects of stressful soil salinity and acidity on the signal exchange processes between soybean and Bradyrhizobium japonicum, and 2) to determine whether or not the addition of signal molecule genistein to B. japonicum can overcome at least part of the inhibition of nodulation, caused by stressful soil salinity and acidity. Salt (sodium chloride) and sulfur (S) were applied. Genistein (0, 5, and 20μ M) was tested. Genistein addition could partially overcome the salt and acidity stresses by increasing soybean yields up to 21% and 23%, respectively. These novel findings may be very useful for planting soybean under salinity and acidity stresses.     

Copper,nitrogen, and Rhizobium japonicum relationships in determinate soybean

A relationship among Cu, N, and Rhizobium japonicum was hypothesized because previous research had shown that (a) 35% or more legumes in the Atlantic Coastal Plain have Cu concentrations of 6 mg kg^‐1 or less, (b) Cu influences N fixation in some legumes, and (c) irrigated soybean (Glycine max L. Merr.) can accumulate most of its N through fixation. Soybean were grown on a Cu‐deficient Norfolk (fine‐loamy, siliceous, thermic Typic Paleudult) loamy sand with 3 fertilizer sources of Cu, 2 strains of R. japonicum, and with or without 336 kg ha^‐1 of N fertilizer. Application of Cu significantly increased the number of pods plant^‐1 suggesting pod abortion in determinate soybean may be caused by low Cu, but seed yield was not increased. Fertilization with N increased vegetative growth, but not total biomass or seed yield. Inoculation with R. japonicum strain 110 significantly increased seed yield by 0.3 Mg ha^‐1 compared to strain 587. The yield increase was similar with or without fertilizer N application indicating strain response was not totally caused by improved N efficiency. There was no relationship between seed yield and nodule occupancy as measured by the ELISA technique.     

A Method for Estimating Sago Palm (Metroxylon sagu Rottb.) Leaf Area after Trunk Formation

Abstract

It is important to measure the individual leaf area and leaf area index (LAI) of sago palm (Metroxylon sagu Rottb.) to determine the appropriate planting density and maintain populations that are highly productive with regard to starch production. However, the accurate estimation of sago leaf area from the entire leaf profile or the projecting area of the plant is not possible. Thus, we developed a method for estimating leaf area of sago palm after trunk formationby integrating the leaflet areas. All leaflets were diagrammatically converted to rectangles, each having the same area asthat of the corresponding leaflet, and these rectangles were arranged on the rachis to initiate the shape of a leaf without overlapping leaflets and gaps between their bases and between their tips. The leaf shape thus produced by the arrangement of these rectangles was represented as ellipsoidal in the apical half and as trapezoidal in the basal half. The ratiosof the estimated to the actually measured area of the apical and the basal half of the leaf were 99?107% and 94?108%, respectively. The ratio of the estimated area of the whole leaf to the measured area was 98?104%. From these results, the method for estimating the whole leaf area by converting the leaflets diagrammatically to rectangles, andcalculating the area as the sum of the ellipsoidal apical half and trapezoidal basal half, is considered to be accurate and simple.