Results of activities to maintain landraces and other material in some European countries in situ before 1945 and what we may learn from them

All three recommendations to maintain landraces in European countries, given in 1927: 1. maintenance by traditional farmers, 2. maintenance by school personnel and pupils, and 3. maintenance by small agricultural institutions, were disregarded. The present outcome: maintenance by genebanks, which often grow landraces and improved cultivars of one crop next to each other, and which often are part of a large agricultural research institute, was advised against.The above observation may be of value to those who at present advocate maintenance of landraces by traditional farmers in developing countries.It is recommended that landraces should be collected and maintained in genebanks as this will result in a partial loss of the material, whereas on farm maintenance (in situ conservation) would lead to a complete loss.     

塑料连栋温室黄瓜生长温度数学模型的研究

为提高塑料连栋温室黄瓜的栽培水平,以能量平衡理论为分析平台,将温室中的空气温度拟合于栽培环境模型中,运用MATLAB程序模拟,并以试验验证模型。结果表明,该模型物理意义明确,便于数值模拟,且模拟结果与试验吻合好。就温室内5月份空气温度模拟而言,回归直线拟合度高,R2=0．8999,绝对误差在±0．85℃之内,平均相对误差9．1％。对回归方母=ax＋b,a与b的标准误差Sa=0．0352〈a／2,Sb=0．1053〈b／2。     

生物炭对亏缺灌溉下温室重壤土栽培番茄产量及品质的影响

探究生物炭对亏缺灌溉下温室重壤土栽培番茄产量和品质的影响,确定番茄产量和综合品质最优的灌水量及生物炭添加量,为重壤土地区温室番茄栽培提供灌水及生物炭施加依据。采用桶栽试验,设置3个生物炭添加量(0,3%,6%,按干土重的百分比计)和3个灌水水平(充分灌溉W1:75%～85%θ_f;中度亏缺W2:55%～65%θ_f;重度亏缺W3:40%～50%θ_f。θ_f为田间持水量),共9个处理。结果表明:无生物炭添加时,亏缺灌溉下番茄产量降低了13.8%～54.0%(P<0.05),果实硬度、果色指数、VC、可溶性固形物、有机酸含量等营养品质指标均显著降低,果型指数、番茄红素则呈现增加的趋势,灌溉水利用效率在重度亏缺下降低了10.9%(P<0.05);在充分灌溉条件下添加生物炭,番茄产量和灌溉水利用效率分别提高了12.3%～22.0%和23.3%～28.6%,可溶性固形物含量降低了6.4%～17.7%(P<0.05),对VC、番茄红素、有机酸含量及外观品质无显著影响;在亏缺灌溉条件下添加生物炭不利于...     

红肉猕猴桃新品种‘红什2号’

‘红什2号’猕猴桃是从‘红阳’בSF0612M’杂交实生后代中选出的红肉新品种。果实广椭圆形,果皮绿褐色,有少量的短茸毛均匀分布在果皮表面,平均单果质量77.64 g,最大102 g,果肉黄绿色,果实横切面呈红、黄绿相间图案,味甜,可溶性固形物含量17.1%,总糖7.26%,总酸0.184%,维生素C含量1.84 mg ? g-1。在四川德阳地区9月中旬成熟,盛果期产量22 500 kg ? hm-2。     

保卫细胞液泡内pH调节的可逆解聚聚合颗粒物性质初探

为研究保卫细胞液泡(GCV)的pH在气孔保卫细胞渗透调节中的作用及蚕豆(Vicia faba)叶片气孔GCV中的颗粒物的性质,本实验采用激光共聚焦显微术配合pH荧光探针BCECF AM的荧光比值法对ABA诱导的气孔关闭过程进行观测,发现:蚕豆气孔关闭过程中GCV的pH升高约0.5(pH5.3→5.8)。分别用pH5.3和5.8的Mes/Tris缓冲液调控离体开放态GCV的pH,透射电镜(4×104倍)观察负染片说明:pH 5.3对开放态GCV液所含颗粒物的线度及分布密度无实质影响;而pH 5.8的处理使取自开放态GCV液所含颗粒物的线度明显增大、分布密度显著减小;非特异性蛋白酶Proteinase K处理可使GCV中的颗粒物消失。基于GCV内颗粒物的线度、形状及对pH调控和对Proteinase K处理的响应,推测此种颗粒物是蛋白质。     

日光温室菠菜品种引种试验初报

对从省内外引进的7个菠菜品种进行的日光温室品种比较试验结果表明,美国鲜美1号、韩国无穷花出苗率达95 %以上,出苗整齐,出苗历期均为3d,毛菜产量分别高达3386 9、32 85 7kg/ hm2 ,商品产量分别达32 95 5、3174 0 kg/ hm2 ,商品率分别达97.3%、96 .6 % ,产值分别达2 6 36 4、2 5 392元/ hm2 ,且抗霜霉病,适宜当地温室推广种植;春秋王外观好,叶片数多,长势旺,产量高,抗霜霉病,商品率高,可搭配种植;青海大圆叶、东京大圆叶出苗率低,长势弱,产量低,易发生霜霉病,不适宜在本地种植     

Biofilter:a promising tool for mitigating methane emission from manure storage

Liquid manure storage may contribute to methane(CH4) emission and this emission can be greatly reduced if appropriate management practices are applied. Biofiltration has been used in other fields for mitigating greenhouse gas(GHG) emission(e.g.,landfill) and shown promise for mitigation CH4 emission from liquid manure storage. It has been reported that biofilter was capable of reducing 80% of CH4 emissions from manure storage. The CH4 removal efficiency is influenced by many factors,including CH4 and O2 concentrations,temperature,moisture,composition of the filter bed,nutrient,and empty bed residency time(EBRT) . Biological conversion of methane of a biofilter is a slow process due to the low water solubility of methane. The residence times(EBRT) between 5 min and 5 h have been used,whereas a typical EBRT of 25 s is used for common biofilter applications. Temperature at which methanotrophic bacteria are active ranges from 10oC to 45oC. The maximum activity is found at around 30oC. The optimal filter bed water content depends on both the gas flow rate and the type of filter bed(soil,compost,etc.) and ranges from 30%-70% of the water holding capacity. Compost is the best material for filter bed. The optimal pH for methanotrophic bacteria is neutral to slightly acidic. Copper and nitrogen compounds especially nitrate are important nutrients to methanotrophic bacteria but their optimal concentrations have not been founded. Phosphorus and other elements such as potassium and manganese are reported to affect the performance of methanotrophic bacteria but need further confirmation.     

百合鳞片离体培养的研究

以'布鲁拉诺'、'提伯'和'索蚌'3个百合品种的鳞片为外植体,比较了不同的消毒方法、不同品种、不同取材部位及接种方法对百合鳞片离体培养的影响.结果表明,最佳的消毒方法是0.1%升汞消毒8 min,污染率较低,成活率最高,可达90.9%,且采用小鳞茎整体消毒可以有效降低污染率.不同百合品种分化小鳞茎的能力有较大差异,分化能力依次为'布鲁拉诺'＞'索蚌'＞'提伯'.百合鳞片不同部位分化小鳞茎的能力从大到小依次为下部、中部、上部.近轴面向上接种的鳞片分化能力强于远轴面向上,小鳞茎再生率最高,可达100%.     

Studies on amoebae and cysts associated with the isolation of Spongospora subterranea f.sp. subterranea in vitro

New evidence is presented to support the contention that the amoeba/cyst colonies isolated from surface-sterilized Spongospora subterranea f.sp. subterranea -infected potato tubers and spore balls have a saprophytic phase but are contaminants and not S. subterranea. Amoebae isolated from infected tissues and spore balls formed colonies associated with bacteria on 1% water agar at 18°C and encysted after 5–7 days. These cysts were morphologically distinct from the resting spores of S. subterranea and were formed singly or in a layer, unlike the spore ball (cystosorus) of S. subterranea . Amoebae, cysts and mixtures of amoebae and cysts in primary, secondary and tertiary subcultures failed to infect tomato roots. PCR amplification of DNA from amoebae, cysts and spore balls using the S. subterranea -specific primer pair SsF/R generated a 434-bp product from S. subterranea spore balls only and not from amoebae or cysts. When an amoeba/cyst-specific primer pair AmF/R was designed and used for PCR amplification, a single 411-bp product was generated from DNA of amoebae and cysts, but not from DNA of S. subterranea spore balls. These results are discussed in relation to earlier reports claiming the successful isolation of S. subterranea and other plasmodiophorids in vitro .     

天水旱作农业区膜侧小麦不同施肥水平增产效应分析

通过不同施肥条件对膜侧小麦水分利用、农艺性状、增产效应、经济效益等方面分析,研究干旱地区膜侧小麦的施肥问题。结果表明:施肥可以提高水分利用率1.1~3.1 kg/(mm.hm2),促进小麦生长发育;不同施肥水平对小麦的增产效应不同:低肥、中肥、高肥3种施肥水平分别比不施肥的对照增产731.5 kg/hm2,1461.0kg/hm2和1 648.5 kg/hm2,增产率分别为25.5%、50.9%和57.4%;经济效益以中肥水平(折合施纯N118.1kg/hm2,P2O594.5 kg/hm2和K2O 60.0 kg/hm2)最高,产值可达2 045.4元/hm2,产投比为2.7∶1。因此,在低、中、高3个施肥水平中,中等施肥最为有效、合理,有利于增产增收。