衡阳高油酸油菜产业发展前景与对策

在综合分析高油酸菜籽油的品质特性及用途的基础上,论述了发展高油酸油菜产业的重要意义,分析了高油酸油菜国内外研究进展与发展现状,分析了衡阳发展油菜生产的自然条件、产业基础、发展潜力,认为在衡阳发展高油酸油菜产业有优势,并就衡阳率先发展高油酸油菜产业提出了建议与对策。     

浅谈四川苎麻产业的优势、前景与发展思路

本文从生态环境、创新实力、生产规模、原麻加工和社会环境等方面分析了四川苎麻产业发展的优势;而苎麻纤维的独特性、苎麻产物的多用途、苎麻生产的轻简化、原麻的耐贮性和种植苎麻的生态效益等特点,使苎麻成为发展潜力较大的朝阳产业;在总结我国苎麻产业发展经验,结合四川苎麻产业发展现状,提出了四川苎麻产业持续稳定发展的新思路.     

大麻产业研究进展Ⅰ.大麻产业概述

简要概括了发展大麻产业的意义,指出:发展大麻产业可以提高农业综合生产能力、培育新的产业集群、构建较完善的产业链、促进传统纺织产业升级和结构调整、符合低碳经济模式与低碳生活方式;介绍了大麻产业的特性,指出:大麻的生态性、资源性、环保型、低碳性以及纤维的功能性;归纳了国内外大麻产业的发展现状.     

大麻产业研究进展 I．大麻产业概述

简要概括了发展大麻产业的意义,指出：发展大麻产业可以提高农业综合生产能力、培育新的产业集群、构建较完善的产业链、促进传统纺织产业升级和结构调整、符合低碳经济模式与低碳生活方式;介绍了大麻产业的特性,指出：大麻的生态性、资源性、环保型、低碳性以及纤维的功能性;归纳了国内外大麻产业的发展现状。     

谈谈大麦质量和制麦质量控制

大麦是啤酒生产的主要原料，控制好大麦质量和制麦质量是保证啤酒质量的关键。在选用一个品种大麦制麦时，首先要了解其品种特性，包括育种过程、农业特性、制麦特性和酿造特性等。     

安乡县蔬菜产业发展现状及对策

阐述了安乡县蔬菜产业近几年在规模化种植、标准化生产、现代化管理及蔬菜加工等方面的特色,指出了产业发展过程中存在的问题,并提出了建议。     

华安县茶叶产业发展的战略取向

华安县是漳州市的茶叶生产大县.总结其发展的成功经验,探讨华安县在茶叶产业发展过程中存在一些急需解决的问题,提出发展的战略与政策导向,对做大、做强华安茶叶产业,有着现实的意义.     

平塘县百香果产业助力脱贫攻坚对策

近年来,百香果种植作为一项短、平、快的增收产业,已逐渐成为平塘县贫困群众发展生产的一项新产业,在助推脱贫攻坚进程中取到了其它产业无法替代的作用,但在产业推进过程中也出现一些不容忽视的问题。就平塘县百香果产业的发展现状进行调研,针对存在的问题加以分析研究,提出相应对策措施,以期为该产业发展有所帮助。     

我国苎麻生产的问题与发展建议

本文从环境保护、生产成本、技术研发、行业联系及政策扶持等方面探讨了我国当前苎麻生产的形势与问题,从天然纤维需求、苎麻特性及农业资源区划等角度分析了苎麻产业的发展前景,并从种植区域布局、机械化生产、清洁化脱胶、多用途及政策等方面重点提出了推动该产业发展的建议。     

产业结构调整背景下天然橡胶生产效率分析——基于广东南华农场的经验数据

改革开放以来,植胶农场试图在产业结构调整中谋取更好、更快的发展.这种调整实质是其他作物替代天然橡胶,减少天然橡胶种植面积的过程,也是生产要素投入内部分配的重新调整过程,必然影响生产效率.研究选取典型代表广东南华农场,利用随机前沿方法测度了1991-2011年天然橡胶生产效率,分析结果显示南华农场生产效率在经历短期下降后,逐步上升并趋于平稳.天然橡胶生产效率变化趋势与橡胶产业发展实际情况基本吻合.作为坚持天然橡胶产业发展的农场,其经验具有借鉴价值.     

南亚热带海岸沙地不同树种叶片化学计量学季节动态研究

养分贫瘠是南亚热带海岸沙地植物生长与分布的主要限制因子之一。本文以南亚热带海岸沙地 5 种树种的叶 片和凋落叶为研究对象，通过对其碳、氮、磷含量及生态化学计量学特征的研究，从树种水平上分析了不同树种鲜叶 与凋落叶养分浓度及重吸收率的动态变化，探讨了不同树种的叶片化学计量特征及与养分含量的关系，以科学评判不 同树种对海岸沙地贫瘠立地的适应性，为沿海防护林的可持续经营提供理论依据。结果表明：海岸沙地上 5 个树种叶 片碳含量普遍较高，而氮、磷含量在不同树种间差异较大，且均呈显著的季节变化。不同树种的平均氮、磷重吸收率 变化范围分别为 25.0%~54.4%和 52.1%~78.1%，其中固氮树种的平均氮重吸收率低于非固氮树种，而其磷重吸收率高 于非固氮树种。在不同季节，不同树种受不同的养分限制。尾巨桉在春秋季为氮限制，在夏冬季为磷限制；厚荚相思 和木麻黄在不同季节均为磷限制；湿地松在春季为氮磷共同限制，夏季为氮限制，秋冬季为磷限制；而潺槁木姜子在 春季为氮限制，夏季为氮磷共同限制，秋冬季节为磷限制。     

向日葵对盐逆境伤害的生理反应及耐盐性研究

栽植于蛭石的向日葵用0．3％，0．6％，0．9％，1．2％NaCl水溶液胁迫处理，20d,40d时测定生理指标。结果表明：盐逆境对向日葵生长有明显伤害，对叶面积的影响大于对株高的影响；膜透性极显著增加，并随处理时间延长呈上升趋势；脯氨酸含量呈初期上升后期下降趋势；光合速率下降原因与盐浓度有关，低盐度胁迫伤害主要是气孔因素造成的，高盐度胁迫伤害则主要来自非气孔因素。     

Sequence of amino acid limitation in triticale

Nitrogen balance experiments were conducted on growing rats to study the sequence of limitation of amino acids in triticale protein. All essential amino acids were added to a triticale-based diet to adjust their total dietary levels to 110% of the requirement. From this complete supplement, individual amino acids were successively removed and nitrogen balance (NB) and biological value of protein (BV) were measured. Based on the extent of response to removal of amino acids, the sequence of limitation was estimated to be lysine, threonine, methionine and valine. The removal of histidine, isoleucine or tryptophan had no effect on NB or BV.     

Sequence of amino acid limitation in triticale

Nitrogen balance experiments were conducted on growing rats to study the sequence of limitation of amino acids in triticale protein. All essential amino acids were added to a triticale-based diet to adjust their total dietary levels to 110% of the requirement. From this complete supplement, individual amino acids were successively removed and nitrogen balance (NB) and biological value of protein (BV) were measured. Based on the extent of response to removal of amino acids, the sequence of limitation was determined to be lysine, threonine, methionine and valine. The removal of histidine, isoleucine or tryptophan had no effect on NB or BV.     

不同生态型小麦品种旗叶光合性能的研究

为明确不同生态型小麦品种的光合作用机制 ,以不同生态型小麦品种为材料研究了小麦旗叶的光合性能。结果表明 ,不同生态型小麦品种旗叶生育期间的气孔限制和非气孔限制具有相同的特点 ,在叶片功能旺盛的前中期 ,光合底物 CO2 对光合速率的限制主要是非气孔限制 ,在叶片老化后期 ,光合底物 CO2 对光合作用的限制同时存在着气孔限制和非气孔限制 ;不同生态型品种小麦旗叶光合功能和碳代谢特性具有与生态型表现相关的规律。春性品种叶绿素含量高 ,光合面积大 ,功能高值期 (RSP、PAD)长 ,叶源量 (L SC)大。半冬性品种光合速率高 ,叶绿素含量较低 ,功能高值期较短 ,叶源量最小。冬性品种叶绿素含量最低 ,功能高值期最短 ,叶面积和光合速率与半冬性品种差异较小     

NaCl胁迫对不同耐盐性水稻某些生理特性和光合特性的影响

选取较耐盐的水稻品种‘HH11’、‘JX99’和盐敏感水稻品种‘YSXD’,设置6个土壤NaCl浓度处理(0、1、2、3、4 g/kg),在防雨棚下盆栽并培育至孕穗期,分析NaCl胁迫对不同耐盐性水稻生理生化及光合特性的影响,结果表明:(1)NaCl胁迫抑制水稻的生长,表现为随着NaCl浓度增加,水稻的株高逐渐降低,但在3～4 g/kg土壤含盐量下耐盐水稻的株高显著高于盐敏感水稻品种。(2)耐盐水稻和盐敏感水稻的可溶性总糖对NaCl胁迫的响应差异明显,在1～4 g/kg NaCl胁迫下,盐敏感水稻叶片可溶性总糖显著降低,但是耐盐水稻可溶性总糖大量合成并积累,并且显著高于盐敏感品种。(3)NaCl浓度增加迫使水稻叶片丙二醛不断积累,导致细胞膜透性逐渐增大,但是耐盐水稻丙二醛的积累量较少,细胞膜受盐害程度显著小于盐敏感水稻。(4)NaCl胁迫抑制了水稻光合速率,但不同的NaCl浓度下导致水稻品种光合速率下降的原因各有差异,其中在0～1 g/kg NaCl胁迫下盐敏感水稻光合速率降低是非气孔因素导致的,而在2～4 g/kg NaCl胁迫下是由气孔因素造成的;0～2g/kg盐浓度下耐盐水稻HH11的光合速率降低是非气孔因素导致的,3～4 g/kg盐浓度处理是由气孔因素导致的;气孔因素是0～4 g/kg盐处理耐盐水稻JX99的光合速率降低的主要原因。(5)盐胁迫下耐盐水稻的叶片蒸腾速率显著降低,并且显著低于盐敏感水稻,相反水分利用效率和气孔限制值却明显升高,并且显著高于盐敏感水稻品种,表明盐浓度增加迫使耐盐水稻气孔阻力增大,减少水分的流失,抑制了蒸腾速率,使耐盐水稻叶片保持较高的水势;同时提高了叶片水分利用效率,碳同化效率提高,以满足耐盐水稻正常代谢生理需求,进行正常生命活动。     

Structural and physiological responses of the C4 grass Sorghum bicolor to nitrogen limitation

Nitrogen (N) is one of the major nutrients influencing photosynthesis and productivity of C₄ plants as well as C₃ plants. C₄ photosynthesis operates through close coordination between mesophyll (M) and bundle sheath (BS) cells. However, how the development of structural and physiological traits in leaves of C₄ plants is regulated under N limitation remains uncertain. We investigated structural and physiological responses of leaves of the NADP-ME-type C₄ grass Sorghum bicolor to N limitation. Plants were grown under four levels of N supply (.05 to .6 g N per 5-L pot). Decreasing N supply resulted in decreases in net photosynthetic rate, stomatal conductance, leaf N and chlorophyll contents, and the activity ratio of phosphoenolpyruvate carboxylase to ribulose 1,5-bisphosphate carboxylase/oxygenase and increases in δ¹³C values and photosynthetic N use efficiency. Low-N leaves were thinner and had smaller photosynthetic cells, especially in M, resulting in lower M/BS tissue area ratio, and contained smaller and fewer chloroplasts. The BS chloroplasts in the low-N leaves accumulated abundant starch grains. The number of thylakoids per granal stack was reduced in M chloroplasts but not in BS chloroplasts. The low-N leaves had thicker cell walls, especially in the BS cells, which might be associated with less negative δ¹³C values, and fewer plasmodesmata in the BS cells. These data reveal structural and physiological responses of C₄ plants to N limitation, most of which would be related to cellular N allocation, light use, CO₂ diffusion and leakiness, and metabolite transport under N limitation.     

梯度干旱胁迫对水稻叶片光合和水分状况的影响

采用温室营养液培养方式,通过添加0%、10%、20%、30%PEG6000模拟干旱胁迫,对水稻幼苗叶片的光合作用和水分状况进行比较分析。结果表明:1)在干旱胁迫下,水稻叶片的光合速率、气孔导度、叶肉导度、总导度和叶绿体内CO2浓度等都显著降低;2)在干旱胁迫条件下,限制光合作用的非气孔限制值并没有显著提高,而气孔限制值则大幅提高;与正常水分条件相比,扬稻6号和汕优63在30%PEG干旱胁迫下气孔限制值分别提高了42%和81%;3)光合速率与气孔导度、叶肉导度、总导度及叶绿体内CO2浓度呈正相关;4)在重度干旱胁迫下(20%和30%),叶片水势和含水量都显著下降,并且叶片水势与气孔导度、叶肉导度和总导度呈正相关。因此,气孔关闭导致的叶绿体内CO2浓度降低是限制光合作用的最主要因素,同时叶片水势的降低增加了叶片内CO2传输的阻力。     

Responses of Lowland,Upland and Aerobic Rice Genotypes to Water Limitation During Different Phases

Rice yield reduction due to water limitation depends on its severity and duration and on the phenological stage of its occurrence. We exposed three contrasting rice genotypes, IR64, UPLRi7 and Apo (adapted to lowland, upland and aerobic conditions, respectively), to three water regimes (puddle, 100% and 60% field capacity) in pots during the vegetative (GSI), flowering (GSII) and grain filling (GSIII) stages. Stress at all the three stages significantly reduced yield especially in lowland genotype IR64. Effect of water limitation was more severe at GSII than at the other two stages. Stress at GSI stage reduced both source activity (leaf area and photosynthetic rate) and sink capacity (tiller number or panicle number per pot). When stress was imposed at GSII, spikelet fertility was most affected in all the three genotypes. In both GSII and GSIII, although leaf area was constant in all the three water regimes, estimated relative whole-plant photosynthesis was strongly associated with yield reduction. Reduced photosynthesis due to stress at any given stage was found to have direct impact on yield. Compared to the other genotypes, Apo had deeper roots and maintained a better water relation, thus, higher carbon gain and spikelet viability, and ultimately, higher biomass and productivity under water-limited conditions. Therefore, screening for these stage-dependent adaptive mechanisms is crucial in breeding for sustained rice production under water limitation.     

Sperm Limitation Produces Male Biased Offspring Sex Ratios in the Wasp,Nasonia vitripennis (Hymenoptera: Pteromalidae)

Haplo-diploid sex determination in the parasitoid wasp, Nasonia vitripennis (Walker), allows females to adjust their brood sex ratios. Females influence whether ova are fertilized, producing diploid females, or remain unfertilized, producing haploid males. Females appear to adjust their brood sex ratios to minimize ‘local mate competition,’ i.e., competition among sons for mates. Because mating occurs between siblings, females may optimize mating opportunities for their offspring by producing only enough sons to inseminate daughters when ovipositing alone, and producing more sons when superparasitism is likely. Although widely accepted, this hypothesis makes no assumptions about gamete limitation in either sex. Because sperm are used to produce daughters, repeated oviposition could reduce sperm supplies, causing females to produce more sons. In contrast, if egg-limited females produce smaller broods, they might use fewer sperm, making sperm limitation less likely. To investigate whether repeated oviposition and female fertility influence gamete limitation within females, we created two treatments of six mated female wasps, which each received a series of six hosts at intervals of 24 or 48 h. All females produced at least one mixed-sex brood (63 total broods; 3,696 offspring). As expected, if females became sperm-limited, in both treatments, brood sex ratios became increasingly male-biased with increasing host number. Interhost interval did not affect brood size, total offspring number, or sex ratio, indicating females did not become egg limited. Our results support earlier studies showing sperm depletion affects sex allocation in N. vitripennis¸ and could limit adaptive sex ratio manipulation in these parasitoid wasps.