自然降温下4个狗牙根品种(系)的生理指标比较

通过对露地栽培自然降温下4个狗牙根(Cynodon dactylon)品种(系)(‘矮败狗牙根'、‘公主'、‘天堂419'和‘HN019')的电导率、丙二醛含量、脯氨酸含量、可溶性糖含量、可溶性蛋白含量、叶绿素含量和超氧化物歧化酶活性7个生理指标的测定,结合模糊隶属函数法,综合评价这4个狗牙根品种(系)的耐寒性.结果表...     

提高石榴坐果率及不同负载量对果实横径、单果重的影响初报

[目的]提高喀什噶尔甜石榴坐果率、增大单果重及果实横径,以增加其商品性.[方法]以6年生喀什噶尔甜石榴为试材,调查春季施肥、花期喷施不同药剂和不同负载量对石榴坐果率、平均单果重、果实横径的影响.[结果]GA3可显著提高坐果率,高于CK 29.0;以上,不同浓度GA3以20和30 mg/L表现最好;GA3与花蕾保、硼砂、磷酸二氢钾及CK之间差异显著.8种施肥组合对头茬花坐果率影响差异不显著;施肥组合a、A可显著提高二茬花的坐果率,分别较CK高5.37;和6.00;.不同负载量对果实横径及单果重的增大效果均为20＞30＞40(果),单株留20、30与40果的果实横径间差异显著,3种留果量的单果重之间无差异.单株留20、30果的单果重均在400 g以上,达到一级优质果.8种施肥组合对单果重的影响无差异.[结论]花期喷施20 和30 mg/L的GA3可显著提高坐果率;施肥组合a、A可显著提高二茬花的坐果率;3种负载量对单果重和果实横径的增大效果依次为20＞30＞40(果).     

狗牙根对5种禾本科杂草化感作用的研究

为探讨狗牙根(Cynodon dactylon Rich.)化感作用在杂草防除中应用的可行性,以培养皿砂培法研究了狗牙根不同材料茎叶水浸提液处理对多花黑麦草(Lolium multiflorum Lam.),一年生早熟禾(Poa annua L.),马唐(Digitaria sanguinalis (L.) Scop.),稗草(Echinochloa crusgalli (L.) Beauv.)和牛筋草(Eleusine indica (L.) Gaerth.)等的化感作用;并利用高效液相色谱(HPLC)法检测了狗牙根茎叶水浸提液中原儿茶酸、咖啡酸、邻羟基苯甲酸、丁香酸、阿魏酸、香草酸、香豆酸、水杨酸、肉桂酸等9种酚酸的含量。结果表明:狗牙根水浸提液处理对5种禾草种子萌发及幼苗生长均产生显著的化感抑制作用(P<0.05),对多花黑麦草、马唐和牛筋草的抑制作用尤为明显;野生普通狗牙根的化感抑制作用强于育成品种。供试的4个狗牙根材料水浸提液中均检测到香草酸、香豆酸和阿魏酸,但仅在部分材料水浸提液中检测到原儿茶酸、咖啡酸、邻羟基苯甲酸、丁香酸、水杨酸和肉桂酸;供试狗牙根材料中,3个材料水浸提液的原儿茶酸含量最高,且其含量的变化与水浸提液处理对禾草种子萌发、幼苗生长的抑制作用强弱顺序基本一致。因此,原儿茶酸可能是狗牙根茎叶中对多花黑麦草、马唐和牛筋草发挥化感抑制作用最大的酚酸物质。     

Improving the Physical and Chemical Properties of a Disturbed Soil Using Drying-bed Biosolids

Disturbed soils might be improved by increasing organic matter content. The objective of this study was to determine if a large application of drying-bed biosolids would improve soil productivity and promote bermudagrass (Cynodon dactylon) and establishment on the Trinity clay soil. Anaerobically digested, air-dried biosolids were applied to Trinity clay (very-fine, montmorillonitic, thermic, typic, pelludert) at rates of 0, 112, 560, and 1120 Mg ha^?1. The biosolids were incorporated into the top 15 cm of the soil and bermudagrass sprigs were planted. Biosolids significantly reduced soil bulk density and soil resistance to penetration when measured during the second and third years after the application. Biosolids increased soil concentrations of organic carbon, nutrients (nitrogen, phosphorus, copper, zinc, iron) and heavy metals (cadmium, chromium, nickel, lead). Bermudagrass biomass production and nutrient uptake were increased due to biosolids, but heavy metals were not significantly transferred from soil to above-ground plant tissue.     

施氮对‘Tifton85’狗牙根光合特性的影响

采用水培试验,研究了不同施氮水平(0.05,0.5,1,2.5,5,10,20,40mmol·L~(-1))对‘Tifton85’牧草型狗牙根(Cynodon dactylon×C.nlemfuensis)光合特性的影响。结果表明,随氮浓度升高,叶干重和茎干重整体呈增加趋势,根干重整体呈相反趋势;植株干重整体呈增加趋势,在氮浓度高于5 mmol·L~(-1)时增加幅度减小。相关性分析表明,植株干重与净光合速率呈极显著正相关(P0.01),而净光合速率与叶片氮含量呈极显著正相关(P0.01)。在氮水平低于5mmol·L~(-1)时,随氮浓度降低,叶片氮含量降低,引起气孔导度降低,导致净光合速率降低。在氮水平高于5mmol·L~(-1)时,随氮浓度升高,胞间CO_2浓度反而降低,进而降低了PSⅡ最大光化学速率和PSⅡ潜在活性,从而减缓了净光合速率增加的幅度。所以,通过合理施氮可以有效提高净光合速率,从而提高‘Tifton85’狗牙根产量。     

Diurnal variation in fecal concentrations of acid-detergent insoluble ash and alkaline-peroxide lignin from cattle fed bermudagrass hays of varying nutrient content

Background

The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash (ADIA) and alkaline-peroxide lignin (APL) for the prediction of fecal output (FO) in cattle was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 bermudagrass [Cynodon dactylon (L.) Pers.] hay diets markedly different in crude protein concentration (79–164 g/kg) with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08:00 and 16:00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06:00, 12:00, 18:00, and 24:00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA.

Results

Fecal concentrations of ADIA and APL were not affected by sampling time (P ≥ 0.22), even though diet affected (P < 0.01) fecal ADIA and APL concentrations. There were no diet × sampling time interactions (P ≥ 0.60). Estimates of FO and dry matter digestibility (DMD) from ADIA and APL were not affected (P ≥ 0.16) by sampling time or the diet × sampling time interaction (P ≥ 0.74). Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different (P ≥ 0.72) from those of total collection among internal markers.

Conclusion

Little variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD.     

水分胁迫条件下几种狗牙根草坪草抗旱性比较研究

以4种不同的狗牙根品种为研究对象,在人工控水条件下,对已成坪的草坪进行自然干旱胁迫处理,结果表明:供试品种在干旱胁迫下,植株绿叶率、叶片相对含水量均呈下降趋势,丙二醛与游离脯氨酸的含量则有所增加,但品种间存在显著差异。综合分析结果,4种狗牙根品种抗旱性强弱为:C3,C1>A3>A5。     

喀什地区日平均温度对棉花产量的影响

通过对喀什地区棉花气候产量指数与日平均温度的相关分析 ,得出影响本地区棉花产量的日平均温度的关键时段为三叶～现蕾生育期和棉花开花盛期内 ,并与相应时段的日平均温度建立了回归模式。然后用巴楚、喀什、莎车、麦盖提、叶城的日平均温度分别与当地县市的棉花产量做了相关普查 ,分析得出影响巴楚、喀什、莎车、麦盖提棉花产量的日平均温度的关键时段也在三叶～现蕾和开花盛期期间 ,而叶城的日平均温度与棉花气候产量的相关系数很小 ,表明叶城温度条件较好 ,热量充足可充分满足棉花生长的需求。最后建立了各地棉花气候产量预报模式 ,具有一定的实用价值。     

冷害胁迫下3个狗牙根品种抗寒性比较研究

对冷害胁迫下3个狗牙根Cynodon dactylon品种的抗寒能力和超氧化物歧化酶(SOD)、过氧化物酶(POD)及POD同工酶的变化进行研究,结果表明:根据低温下细胞膜的伤害程度,3个狗牙根品种抗寒能力的强弱顺序为新农一号狗牙根C.dactylon cv.Xinnong No.1>喀什狗牙根C.dactylon cv.Kashi>矮生天堂草C.dactylon×C.trasvaalensis,且在根茎上反映更加明显;POD,SOD的活性均表现出先上升后下降的趋势,植株抗寒能力的强弱可能与它们的活性及其持续时间的长短有一定的正相关性;聚丙烯酰胺凝胶电泳表明,抗寒性越强的狗牙根品种POD同工酶条数也越多,且在冷害适应中未有新的同工酶谱带出现.