Brassinolides have a small effect on vegetative growth,and increase reproductive growth of pistachio trees Cv. Owhadi

The effects of different applications of 24-epi-brassinolideon the physiology and yield of ‘Owhadi’ pistachio trees was investigated in Iran over an off and on year. Plants were treated by 24-epi-brassinolide at 0, 0.25, 0.5, 0.75 and 1mgl^?1at green tip and tight cluster of bud stage. Brassinolide decreased the incidence nut physiological disorders and increased yield. The sprays decreased the incidence of inflorescence bud abscission, fruit abscission, misshapen nuts, blank, early splitting and indehisced shell compared with the controls. In both on and off years, the effect of brassinolide was dependent on the time of application and concentration used. Application of this compound, especially at tight cluster stage of buds, increased indehisced shell and yield in both on and off years. Brassinolides appear to play a key role in the growth and development of pistachio.     

2,4-D在柑橘果实留树保鲜中的作用和可能机制研究

以‘锦橙’（Citrus sinensis Osbeck）为材料，比较2,4-D不同浓度、不同施用时期对锦橙果实落果率和品质的影响，同时研究2,4-D在柑橘果实留树保鲜中的可能机制。结果发现，在盛花后200 d（柑橘果实转黄期）施用20 mg • L-1的2,4-D，能显著降低柑橘果实留树越冬的落果率，且对果实品质无不良影响，果实能够留树保鲜50 d左右。研究还发现，2,4-D处理能延缓果蒂离层的形成，抑制细胞壁降解相关酶基因CX16、PG2、PME1、PME2的表达。综上所述，2,4-D能够用于锦橙果实留树保鲜，其主要机制可能是抑制细胞壁降解和离层形成。     

盐胁迫下不同耐盐性的陆地棉品种脱落规律及机理

NaCl胁迫下研究了三个不同耐盐水平(不耐盐、稍耐盐、较耐盐)的棉花材料的蕾、花、铃脱落及其规律.低浓度NaCl(0.20%)仅对耐盐性差的材料的脱落率的有显著影响,不耐盐材料的脱落率的次序是蕾＞花＞幼铃＞大铃,对稍耐盐材料的蕾、花也存在显著影响.在高浓度NaCl(0.40%)下,脱落率取决于材料的耐盐性,其脱落率次序是:不耐盐材料＞稍耐盐材料＞较耐盐材料,耐盐性与脱落率呈负相关,耐盐性高的材料其脱落率较低.不同耐盐性能的材料的蕾、花、铃脱落率存在显著差异;不耐盐材料的脱落率依次为:蕾=花＞幼铃＞大铃;较耐盐材料的脱落率依次为:蕾＞花=幼铃＞大铃;较耐盐材料的脱落率依次为:蕾＞幼铃＞花,在NaCl(0.40%)以下的浓度都不会对较耐盐材料的大铃产生影响.     

Abscisic acid drenches can reduce water use and extend shelf life of Salvia splendens

Inadequate watering of potted ornamental plants during retail can cause a decline in quality as well as plant death. Abscisic acid (ABA) is the main phytohormone controlling plant responses to drought stress, including regulation of stomatal opening and closure. ABA may become available for the greenhouse industry in 2010. The objective of this study was to determine whether exogenous ABA applications can be used to induce stomatal closure and reduce water loss from the substrate. We drenched salvia (Salvia splendens F. Sellow. ex Roem & Shult.) ‘Bonfire Red’ with 50 mL of ABA solutions at concentrations of 0, 250, 500, 1000, and 2000 mg L⁻¹, after which plants were no longer irrigated. ABA drenches slowed down substrate water loss by reducing transpiration in a dose-dependent manner. Stomata closed within 3 h after ABA treatment, decreasing transpirational water loss. However, ABA drenches also caused abscission of lower leaves, resulting in approximately 60% leaf loss with 2000 mg L⁻¹ ABA. ABA drenches with 250 mg L⁻¹ and 500 mg L⁻¹ increased the shelf life of salvia ‘Bonfire Red’ by 3 days, without excessive leaf abscission. ABA can be used to increase the shelf life of salvia, but the lowest effective concentration should be used to minimize leaf abscission.     

快速高效提取荔枝幼果和离区组织RNA的新方法）

 以荔枝幼果和离区为材料,以N–十二烷基肌氨酸钠（LSS）为RNA提取液的主要成分,建立了一种简单快速高效适合于荔枝幼果和离区总RNA提取的新方法,简称LSS法。该法提取RNA的过程只需2 h,且质量高,幼果和果柄RNA的28S/18S值分别为1.7和1.9,RNA完整性（RIN）值分别为9.7和10.0,分别为380和450 μg · g-1,A260/A280值分别为1.80和1.89。将提取的RNA经DNA酶消化后反转录成cDNA进行PCR,扩增出预期长度的目的片段,满足进行后续基因表达的要求。LSS法操作简单快速,对微量组织样品是一种有效的RNA提取方法。     

乙烯诱导下柑橘果实离层SSH文库的构建及分析

为发掘柑橘果实脱落过程中的关键基因,构建了受乙烯诱导的柑橘果实离层SSH文库,经蓝、白斑筛选,菌液PCR检测和测序验证,共获得385条有效EST.经聚类拼接得到单基因簇30个,其中片段重叠群28个、单一EST序列2个.经BLASTX比对NCBI的非冗余蛋白数据库,在这些ESTs中,28个找到同源序列,2个无匹配;BLAST2GO功能注释表明:这些单一基因主要涉及衰老、抗逆防御、细胞壁水解、信号转导等功能.     

大豆光合生理生态的研究 第18报 不同株型大豆某些生理特性的研究

对美国扁茎大豆、中国有限结荚习性大豆7514及其杂交后代新品系94-1-1、94-1-6某些生理特性及部分产量构成因素的测试分析结果表明：1．新品系材料从结荚期开始光合速率明显高于亲本。光合速率的日变化显示，后代材料类似于美国扁茎大豆，与中国普通大豆差异较大。2．比叶重的变化也表明，后代材料高于美国扁茎与中国普通大豆7514，尤其在结荚期和鼓粒期表现更为突出。3．水分利用效率的变化表现为，前期差异不大，从鼓粒期开始，后代材料明显优于亲本。4．新品系与亲本材料相比具有特异的花序性状和叶片着生态势以及生殖生长期较大的光合速率，从而降低大豆花荚脱落率。     

病害对3个砂梨品种早期落叶的影响

由于一些侵染性病害的影响,浙江省主要梨产区出现早期落叶严重的现象,严重影响了砂梨产业的发展。通过对浙江省杭州市商业梨园主栽品种的田间调查发现,不同品种对病菌的抵抗能力不同。圆黄为黑斑病的易感品种,但对炭疽病的抗性较强;黄花和翠冠较抗黑斑病,但黄花炭疽病的发病率较高;3个品种的锈病发病率没有显著差异。病菌侵染和落叶时间的相关性分析表明,病菌侵染后翠冠和圆黄落叶较黄花早;受黑斑病菌侵染的叶片最易脱落,而梨炭疽病菌和梨锈病菌不易引起落叶,仅在后期形成穿孔。总体上圆黄早期落叶现象最为严重。受梨黑斑病菌侵染后,叶片诱导POD活性的增加来抵御病原菌的侵染。     

Effects of 30 years of cropping and tillage systems on surface soil test changes

Abstract

A common belief is that no‐till systems with adequate fertility will improve soil quality over other tillage systems. The objectives of this study were to determine if crop phase, tillage systems, and n rate in a long‐term rotation affected soil chemical analyses in the surface 15 cm of soil and to evaluate the trend in chemical analyses. To test this hypothesis, surface soil samples were taken from a long‐term (30‐year) cropping and tillage study. This study was initiated in 1965 on a Harney silt loam soil in Central Kansas with every phase of the wheat‐sorghum‐fallow (WDF) rotation included each year. Tillage systems included clear‐till (CT), reduced‐till (RT), and no‐till (NT). In 1975, four nitrogen (N) rates (0, 22, 45, 67 kg N ha¹) were incorporated by subdividing the tillage plots. Topdressed N, as ammonium nitrate, was the only fertilizer added throughout the duration of the study. Soil samples were taken at depths of 0 to 7.5 and 7.5 to 15 cm in all plots in 1965 and in 1995. In 1998, soils on 1997 sorghum plots were samples in 2.5‐cm increments to 15 cm. Samples from all dates were analyzed for pH, available phosphorus (AP), and organic matter (OM), and deviations from the controls from 1965 to 1995 were assessed by subtracting 1995 results from 1965 results. The change in soil pH showed a crop phase by sample depth interaction. In the wheat phase, pH in the top 7.5 cm increased by 0.19 and increased by 0.28 in the 7.5–15 cm layer. In the fallow phase, pH increased by 0.04 and 0.35 in the top 7.5 cm and 7.5–15 cm layers, respectively. The pH change for sorghum was intermediate for both depths. The increase in overall pH from 1965 to 1995 was unexpected and contrary to normal expectations of a decrease over time. Soil OM was not changed significantly over the 30 years of the study, suggesting that OM buildup or depletion is very slow under this cropping system on a nearly level soil with minimal soil erosion. Increasing the rate of N application significantly reduced pH in the upper increment samples, but had little effect on pH below 10 cm. The NT system had the lowest surface increment in pH, but differences among tillage systems were minimal below 7.6 cm. The AP was highest for NT in the surface increment, but for CT at deeper depths. Likewise, OM was highest for NT in the 2.5 cm increment and the CT at deeper increments. Under the present N management, pH may reach levels where herbicide effectiveness and phosphorus availability could be affected adversely. Deep tillage by one‐way or mold‐board plowing might be an interim solution to raise the pH before liming is implemented or P fertilizer is added to maintain adequate AP throughout the top 15 cm. Nitrogen management may need to be changed to some form of band‐type placement to reduce the total N applied. Under the conditions of this study (WSF, reduced tillage, and 57 cm annual precipitation), soil OM increased very slowly.