改良CTAB法提取益智基因组DNA

益智叶片中多酚和多糖等杂质的含量较高,为获得高质量的益智基因组DNA,试验在传统CTAB法的基础上加以改良,提取益智基因组DNA,并对所得DNA的质量和浓度进行了检测。结果表明,改良后的方法较之传统方法简单高效,所获得的基因组DNA质量较好,OD260/OD280在1.7~2.0之间,RNA消化彻底,DNA无明显降解,进行ISSR分析条带清晰,多态性好。适合于进行以PCR为基础的DNA多态性的研究。     

西方蜜蜂(Apis mellifera)不同蜂种及其杂交组合采粉力研究

“浙农大 1号”意蜂 (A .m .ligusticaEa)分别与喀尼鄂拉蜂 (A .m .carnica)、卡尔巴阡蜂 (A .m .carpati ca)、高加索蜂 (A .m .caucasica)、乌克兰蜂 (A .m .acervorum)、东北黑蜂 (A .m .spp .)进行正反杂交组配。在山东玉米花期 ,考察这 6个西方蜜蜂蜂种及 10个正反杂交组合的 95个试验蜂群的蜂花粉生产性能 ,分析杂交一代的杂种优势。结果表明 ,K是 6个纯种中蜂花粉产量最高的蜂种 ,Ea位居第二 ,Ea×D是所有纯种和杂交组合中蜂花粉产量最高的蜂种 ,是培育蜂花粉高产组合的蜂种。杂交组合Ea×D和W×Ea的蜂花粉生产性能具有明显的杂种优势 ,其杂种优势率分别达到 49.5 %和 2 1.1%,其他 8个杂交组合表现为杂种劣势     

Effect of improved fallow on crop productivity, soil fertility and climate-forcing gas emissions in semi-arid conditions

The impacts of fallow on soil fertility, crop production and climate-forcing gas emissions were determined in two contrasting legumes, Gliricidia sepium and Acacia colei, in comparison with traditional unamended fallow and continuous cultivation systems. After 2 years, the amount of foliar material produced did not differ between the two improved fallow species; however, grain yield was significantly elevated by 55% in the first and second cropping season after G. sepium compared with traditional fallow. By contrast, relative to the unamended fallow, a drop in grain yield was observed in the first cropping season after A. colei, followed by no improvement in the second. G. sepium had higher foliar N, K and Mg, while A. colei had lower foliar N but higher lignin and polyphenols. In the third year after fallow improvement, a simulated rainfall experiment was performed on soils to compare efflux of N₂O and CO₂. Improved fallow effects on soil nutrient composition and microbial activity were demonstrated through elevated N₂O and CO₂ efflux from soils in G. sepium fallows compared with other treatments. N₂O emissions were around six times higher from this nitrogen-fixing soil treatment, evolving 69.9 ngN₂O–N g⁻¹soil h⁻¹ after a simulated rainfall event, compared with only 8.5 and 4.8 ngN₂O–N g⁻¹soil h⁻¹ from soil under traditional fallow and continuous cultivation, respectively. The findings indicate that selection of improved fallows for short-term fertility enhancement has implications for regional N₂O emissions for dry land regions.     

玉米属（Zea）八个亚种多倍体的诱导

利用改良Ｌ．Ｄ．Ｃｕａ法对玉米属（Ｚｅａ）的八个亚种进行秋水仙素多倍体诱变，并经三年的自交纯合已获得六个玉米亚种的多倍体。这六个亚种为糯质型（ＺｅａｍａｙｓＳｉｎｅｎｓｉｓ）、马齿型（Ｚｅａｍａｙｓｉｎｄｅｎｔａｔａ）、爆裂型（Ｚｅａｍａｙｓｅｕｅｒｔａ）、硬粒型（Ｚｅａｍａｙｓｉｎｄｕｒａｔａ）、有稃型（Ｚｅａｍａｙｓｔｕｎｉｃａｔａ）、分蘖型（Ｚｅａｍａｙａ．Ｌ．Ｖａｒｃａｎｉｎａ）．     

玉米黄改系耐旱性材料筛选与鉴定方法研究

在正常水分、花期干旱、全生育期干旱3种水分条件下,对25份玉米黄改系材料和亲本黄早四进行耐旱性鉴定并筛选耐旱材料。结果表明,花期干旱胁迫和全生育期干旱胁迫条件均可进行耐旱性鉴定。在干旱胁迫条件下,穗部性状(单穗穗重、单穗粒重、百粒重和耐旱系数)、粒型性状(粒长)和花期性状(开花吐丝间隔,ASI)能够作为耐旱筛选性状,株型性状作为筛选的参考性状,粒型性状(粒宽和粒厚)不能作为筛选性状。根据干旱胁迫的筛选,获得9份黄改系耐旱性材料。     

新疆褐牛细管冻精改良当地蒙古牛效果分析

用新疆褐牛细管冻精为父本,以新疆博尔塔拉州本地蒙古牛为母本进行杂交,即采用人工授精的方法获得杂交F1。褐蒙F1,初生重公犊比蒙古牛提高28．26％,母犊提高27．23％,断奶重公犊提高92．04％,母犊提高92．16％。同龄褐蒙F1屠宰率、净肉率比本地蒙古牛提高6．6％和8％。平均每头褐蒙F1牛可增肉70．3kg,按每千克牛肉25元计算,增效1758元。细管冻精配种可降低成本130元。     

安格斯杂交肉牛放牧采食量及营养物质消化率的测定

春季同时用全收粪法和内源指示剂法(酸不溶灰分,AIA)测定安格斯杂交成年公牛日采食牧草量和牧草营养物质消化率.研究表明,安格斯杂交公牛日采食牧草量为20.269 kg,牧草营养物质消化率相应为干物质78.82%、粗蛋白86.53%、粗脂肪75.11%、中性洗涤纤维80.07%、酸性洗涤纤维69.64%.此外,春季牧草营养成分偏低,故需进行适量补饲来满足杂交肉牛的生长需要.     

The flora and structure of farmland hedges and hedgebanks near to pheasant release pens compared with other hedges

On farms where shooting takes place, hedgerows leading from woodlands with release pens are often used by pheasants as corridors for accessing game crops. We compared shrub and ground flora structure and species composition in hedges near to and away from release sites with a wide range of release sizes, at 109 game estates in four regions in England in 2002 and 2003. There was more bare ground, fewer stable perennial plant species, more weeds and fewer tree and shrub seedlings in hedges near to release sites compared to our controls, sometimes only when the nearby release exceeded a certain threshold. Alongside hedges there were more weeds on hedgebanks near to release sites, and depending on hedge size, fewer stable perennial species or fewer tree and shrub seedling species. While the woody structure of the hedge itself was not substantially different, shrub leafiness within hedges at 10-20 cm off the ground was reduced in all except very short hedges near to releases. We argue that the differences we observed were due to the presence of pheasants in those hedges during the late summer and autumn following release and not to pen siting or game management factors. We hypothesize that where larger accumulations of pheasants occur in hedges, the changes to ground flora species composition we observed were due to increased soil fertility and soil disturbance. The effects on mature shrub leafiness and woody seedlings were probably caused by direct pecking. Our study involved many sites and some of the effects identified were subtle. Our data on release size enables us to suggest how to minimise these effects where this is considered important, for example where hedgerows are recognized as particularly valuable or vulnerable.     

湖北恩施茶树良种筛选研究

选取10个湖北恩施茶树品种,对其树冠性状、理化成分及所加工炒青绿茶的品质进行研究。结果表明:福鼎大白茶和龙井43是绿茶加工的最适宜品种;恩苔1号、恩苔2号和该地区群体种在品质上有一定优势,应强化后续研究,以保持其优良种性得到更好的利用。     

垦稻11号良种良法技术研究

通过对垦稻11号进行不同插期、不同密度和不同施肥量级的试验,找出其在我场大田生产上推广繁育的合理栽培方法和模式。试验结果表明,垦稻11号的最适宜插秧时间是5月13～23日,插秧规格30 cm×13 cm为宜,每穴3～5苗,施肥量应以处理2为准,N∶P∶K比例为2∶1.05∶0.65。