Yield performance of spring wheat improved by regulated deficit irrigation in an arid area

A field experiment was conducted in 2003 and 2004 growing seasons to evaluate the effects of regulated deficit irrigation on yield performance in spring wheat (Triticum aestivum) in an arid area. Three regulated deficit irrigation treatments designed to subject the crops to various degrees of soil water deficit at different stages of crop development and a no-soil-water-deficit control was established. Soil moisture was measured gravimetrically in the increment of 0–20 cm every five to seven days in the given growth periods, while that in 20 increments to 40, 40–60, 60–80, and 80–100 cm depth measured by neutron probe. Compared to the no-soil-water-deficit treatment, grain yield, biomass, harvest index, water use efficiency (WUE), and water supply use efficiency (WsUE) in spring wheat were all greatly improved by 16.6–25.0, 12.4–19.2, 23.5–27.3, 32.7–39.9, and 44.6–58.8% under regulated deficit irrigation, and better yield components such as thousand-grain weight, grain weight per spike, number of grain, length of spike, and fertile spikelet number were also obtained, but irrigation water was substantially decreased by 14.0–22.9%. The patterns of soil moisture were similar in the regulated deficit treatments, and the soil moisture contents were greatly decreased by regulated deficit irrigation during wheat growing seasons. Significant differences were found between the no-soil-water-deficit treatment and the regulated soil water deficit treatments in grain yield, yield components, biomass, harvest index, WUE, and WsUE, but no significant differences occurred within the regulated soil water deficit treatments. Yield performance proved that regulated deficit irrigation treatment subjected to medium soil water deficit both during the middle vegetative stage (jointing) and the late reproductive stages (filling and maturity or filling) while subjected to no-soil-water-deficit both during the late vegetative stage (booting) and the early reproductive stage (heading) (MNNM) had the highest yield increase of 25.0 and 14.0% of significant water-saving, therefore, the optimum controlled soil water deficit levels in this study should range 50–60% of field water capacity (FWC) at the middle vegetative growth period (jointing), and 65–70% of FWC at both of the late vegetative period (booting) and early reproductive period (heading) followed by 50–60% of FWC at the late reproductive periods (the end of filling or filling and maturity) in treatment MNNM, with the corresponding optimum total irrigation water of 338 mm. In addition, the relationships among grain yield, biomass, and harvest index, the relationship between grain yield and WUE, WsUE, and the relationship between harvest index and WUE, WsUE under regulated deficit irrigation were also estimated through linear or non-linear regression models, which indicate that the highest grain yield was associated with the maximum biomass, harvest index, and water supply use efficiency, but not with the highest water use efficiency, which was reached by appropriate controlling soil moisture content and water consumption. The relations also indicate that the harvest index was associated with the maximum biomass and water supply use efficiency, but not with the highest water use efficiency.     

兰州百合微繁的研究

以兰州百合的鳞茎增殖为基础,进行了离体微繁研究。鳞茎增殖的适宜激素组合为0.9mg/LBA 0.1~0.2mg/LNAA。培养基中总离子浓度和氮浓度过高或过低都会影响兰州百合增殖,3种基本培养基N6、MS、和1/2MS以N6增殖效果最好。适当提高糖浓度对鳞茎增殖有促进作用,在各处理中以蔗糖浓度为40g/L增殖倍数高。兰州百合的适宜生根培养基为1/2MS IBA0.1mg/L,生根率达100%,生根苗移栽成活率达90%。     

扁桃幼苗对水分胁迫的生理响应

以2 a生的扁桃幼苗为试材,研究了水分胁迫对扁桃幼苗叶片相对含水量、渗透调节能力、细胞膜透性、膜脂过氧化以及酶保护系统的响应。结果表明,在受到轻度和中度胁迫过程中,扁桃幼苗叶片的Pro、RCC、MDA以及SOD都出现相似变化趋势,细胞膜透性和膜脂过氧化程度逐渐加剧,渗透调节能力和酶保护系统增强;在重度胁迫时,其生理调节能力下降,当达到土壤含水量3.77%以下的重度胁迫时,就会受到旱害;总体而言,两个供试品种扶兹(Fritz)和那普瑞尔(Nonpareil)都具有较强的抗旱适应性。     

Baseline sensitivity of <Emphasis Type="Italic">Phytophthora capsici</Emphasis> to the strobilurin fungicide benzothiostrobin and the efficacy of this fungicide

Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) has seriously threatened global banana production. Recently, identification of Foc TR4 in the Caribbean and Mozambique has aroused widespread concern because it may be directly related to food security for millions of people in Africa and Latin America. To identify a resistant or highly resistant germplasm, 129 accessions were evaluated for Foc TR4 resistance in greenhouses and 100 of them were also assessed in the field. In total, 10 accessions were highly resistant (HR) to Foc TR4; these include four from the AA group, two from the BB group, one of the East African highland bananas (EAHBs), two plantains, and one from wild relatives of banana. Of these, Pahang (AA), Calcutta 4 (AA), and Musa itinerans exhibited the highest degree of resistance with an index of disease (ID2) less than 10, and Foc TR4 could not infect any of them in the field. Furthermore, 31 accessions from AA, AB, AAB, AAAB, and ABB groups and wild relatives were identified as a resistant (R) germplasms. All tested EAHBs and plantains exhibited resistance or high resistance to Foc TR4 infection. Our results provide valuable genetic resources for banana breeding and for studying the mechanisms underlying Fusarium wilt resistance. Furthermore, evaluation of EAHBs and plantains provided a rational for local banana producers and researchers to grow EAHBS and plantains.     

茉莉酸甲酯对高寒地区设施延后栽培葡萄生理的影响

在高寒地区设施延后栽培葡萄生产中,为降低不利气候的影响,提高葡萄植株抵御灾害的能力,研究茉莉酸甲酯(MeJA)处理对转色期葡萄抗性的影响。以‘红地球’葡萄为试材,设置了0(CK)、0.001、0.01、0.1 mmol/L 4种茉莉酸甲酯处理浓度,在葡萄转色期（11月上旬）对叶片喷施后,进行相关指标的测定。研究结果表明,0.001 mmol/L茉莉酸甲酯处理,葡萄叶片中叶绿素含量降低了23.5%（叶绿素a降低29%,叶绿素b变化不显著）;其净光合速率、气孔导度、蒸腾速度分别比对照减少14.9%、22.4%、12.5%;叶片中丙二醛的含量减少;SOD、POD、CAT酶的活性分别增强了23%、41%、62%;脯氨酸含量上升。0.01 mmol/L茉莉酸甲酯处理,使细胞膜电导率降低了25.5%;并提高SOD酶活性58%。外源施入茉莉酸甲酯能有效防止细胞膜的过氧化反应,抑制了植物的光合作用,增强保护性酶的活性,提高了其抵抗逆境的能力。     

1-MCP对‘徐香’猕猴桃冷藏期间冷害与果实品质的影响

【目的】探讨1-甲基环丙烯(1-MCP)处理对‘徐香’猕猴桃0℃贮藏期间冷害和贮藏品质的影响,为猕猴桃的采后贮藏保鲜研究提供参考。【方法】以‘徐香’猕猴桃果实为材料,用0.5μL/L的1-MCP在20℃下处理果实24h,以蒸馏水处理的果实为对照,然后将其置于0℃下贮藏90d,每隔10d取样测定冷害指数、冷害率、呼吸速率、乙烯释放速率、细胞膜透性、MDA含量、硬度、可溶性固形物含量、可滴定酸含量、质量损失率和腐烂率,分析1-MCP处理对猕猴桃冷藏冷害及果实品质的影响。【结果】0.5μL/L的1-MCP处理显著延缓并减轻了猕猴桃冷害的发生,1-MCP处理的果实较对照晚20d发生冷害,0℃贮藏90d后的冷害率仅为对照的32.35%;贮藏10d后果实出现呼吸高峰,1-MCP处理和对照果实的呼吸速率分别为7.25和7.98mg/(kg·h),果实的乙烯释放高峰则在贮藏60d时出现,1-MCP处理显著抑制了果实乙烯的释放,1-MCP处理和对照乙烯释放速率分别为0.016和0.048μL/(kg·h);1-MCP处理可以延缓猕猴桃果实硬度和可滴定酸含量的下降,但对可溶性固形物含量的影响不明显;1-MCP处理显著抑制果实贮藏后期细胞膜透性和MDA含量的增加;贮藏90d后,对照和1-MCP处理果实的质量损失率分别为0.603%和0.278%,腐烂率分别为10.3%和2.7%。【结论】0.5μL/L 1-MCP处理可以减轻‘徐香’猕猴桃果实冷藏冷害的发生,并能较好地保持果实品质。     

甘肃花卉根际线虫的营养类群结构

2006－2007年,对甘肃省酒泉、定西、天水等地9个花卉制种繁育、示范生产基地种植的旱金莲、唐菖蒲、孔雀草、万寿菊、波斯菊、大丽花等56种花卉根际线虫类群进行了研究。经鉴定111076条线虫分属43个属,4个营养类群（食细菌、食真菌、杂食/捕食和植物寄生线虫）,其中有益的非植物线虫属32个,有害的植物线虫属11个,占总调查属数量的1/4,相对比例较大,特别是垫刃属（Tylenchus）和 丝尾垫刃属（Filenchus）的线虫出现的频率较高,涉及花卉51种和42种,分别占调查花卉总数的91％和75％。本研究结果将为进一步分析甘肃省各种花卉根际线虫的潜在风险提供参考数据,为甘肃省花卉进出口贸易的线虫争端提供谈判和决策依据。     

茶树根际土壤氮素组成及其吸收利用效率分析

为了揭示茶树种植年限对土壤氮素组成及茶树氮素吸收利用的影响。以植茶0、4、9和30年的铁观音茶树根际土壤为材料，分析不同树龄茶树根际土壤可溶性有机氮（soluble organic nitrogen，SON）组成及其对茶树氮素吸收利用效率的影响。结果表明，随着茶树树龄的增加，根际土壤氨基酸SON含量从46.83%下降至22.71%，非氨基酸SON含量则从53.17%上升至77.29%。氨基酸含量分析表明，不同树龄茶树根际土壤共检测到14种氨基酸，其中5种疏水氨基酸含量随着茶树树龄的增加显著上升，8种亲水氨基酸含量随着茶树树龄的增加显著下降。茶树氮素吸收利用效率结果表明，随着茶树根际土壤年限的增加，茶树氮素吸收效率、氮素生理利用率、氮素效率、氮素经济效益等均呈现下降趋势。相关性分析表明，土壤年限与土壤氨基酸SON、亲水氨基酸含量、氮素效率、氮素吸收效率、氮素生理利用率、氮素经济效率等呈显著或极显著负相关，其他指标则相反。可见，随着茶树树龄的增加土壤氮素组分及氨基酸含量发生显著变化，进而影响茶树对土壤氮素的吸收与利用。结果为酸化茶园土壤修复提供一定的理论依据。     

兰州百合微繁的研究

以兰州百合的鳞茎增殖为基础，进行了离体微繁研究。鳞茎增殖的适宜激素组合为0.9 mg/L BA +0.1~0.2 mg/L NAA。培养基中总离子浓度和氮浓度过高或过低都会影响兰州百合增殖，3种基本培养基N6、MS、和1/2MS以N6增殖效果最好。适当提高糖浓度对鳞茎增殖有促进作用，在各处理中以蔗糖浓度为40 g/L增殖倍数高。兰州百合的适宜生根培养基为1/2MS+IBA0.1 mg/L，生根率达100%，生根苗移栽成活率达90%。