Effects of Seed Maturity of Turf-Type Tall Fescue on the Seed Vigor and the Optimal Harvesting Time

By assay of accelerated aging germination, germination index, vigor index, seedling length,seedling weight, electric conductivity, dehydrogenase activity, ATP content and acid phosphoesterase activityduring seed development of turf-type tall fescue, the seed vigor of tall fescue were studied. Combining withseed moisture content and yield, the optimal harvesting time of tall fescue was determined. The results indica-ted that the seed vigor increased continuously along with seed maturity, and the higher seed vigor was achievedat 19th day after perk anthesis and maintained continuously until 31st day after peak anthesis. At 25th day af-ter peak anthesis, the highest yield of 3 533 kg ha-1 and the good quality of seeds of tall fescue were harvestedwith 32.19% moisture content. From 22nd to 31st day after peak anthesis, the seed yield of 3 300 kg ha-1 andthe good quality seeds of tall fescue were harvested with 40 -12.43% moisture content, and the span was theoptimal harvesting time.     

预防楼板缝开裂的几项技术措施

本文对如何控制楼板裂缝进行了论述,并提出了几项预防楼板缝开裂的技术措施。     

液态地膜复合成膜材料的试验研究

分析了液态地膜成膜工艺对骨架材料和填充材料的要求 ,根据试验结果 ,确定了液态地膜材料的主要组分。分别以NH4 OH ,NH4 HCO3和HN4 HCO3·NH2 COONH4 为海带消化剂进行替代Na2 CO3的试验 ,结果表明 ,用NH4 HCO3·NH2 COONH4 为消化剂时 ,其消化效果与Na2 CO3的相同 ,褐藻酸提取率可达 12 %～ 16% ;用Na2 SO3,CaClO4 和H2 O2 对海带脱色后 ,制得膜的透光率仅提高了 3 %。对 4种变性淀粉的溶解特性进行观察分析 ,以磷酸淀粉为填充材料 ,可有效地改善成膜材料的凝胶特性和调配特性。提出了一种以海带、磷酸淀粉和NH4 HCO3·NH2 COONH4 为原料 ,用半干法混炼工艺制备液态地膜复合成膜材料的方法 ,用该材料制备的膜的透光率为 47%     

Phosphorus Accumulation and Translocation in Wheat as Affected by Cultivar and Nitrogen Fertilization

To improve nutrient management strategies in wheat more information is needed about the interaction effects among nutrients in their uptake and redistribution in the plants, in relation to different genotypes. Therefore, two bread ( T. aestivum L.) and two durum ( T. durum Desf.) winter wheat cultivars were grown in the field for 2 years (1986, 1987) in a silty-clay soil under different nitrogen (N) levels, in Northern Greece. Nitrogen at a rate of 150 kg ha⁻¹ was applied before planting or 100 kg ha⁻¹ before planting and then 50 kg ha⁻¹ at early boot stage. Cultivar differences in phosphorus (p) concentration were observed only in vegetative parts but not in the grain. Maximum p accumulation was observed either at anthesis or at maturity. During grain filling dry matter and p accumulation in the grain followed almost the same pattern. Phosphorus translocation efficiency of the cultivars at the 2 years ranged from 70.7 to 84.3 % and the amount of p in the grain derived from translocation 52 to 100 %. Phosphorus translocation efficiency was weakly correlated with p content in grain only in 1986, while phosphorus harvest index (PHI) was positively correlated with harvest indst (HI) both years (r = 0.82** in 1986 and 0.75** in 1987). Nitrogen application mainly affected p accumulation of the cultivars via its effect on biomass production. The split N application promoted slightly the p uptake in 1987 and this resulted in the reduction of both the contribution of the translocated p to the grain and the efficiency of p utilization for total biomass. Results indicated that p accumulation and translocation and the efficiency of p utilization in wheat were mainly determined by the genotype in relation to environmental condition of growth.     

航天诱变黔草1号高羊茅内生真菌分布特点及分离培养研究

为探明内生真菌在航天诱变材料黔草1号高羊茅中的分布情况和种类,利用光学显微镜进行镜检观察,对被侵染的航天诱变材料高羊茅展开内生真菌分离培养研究。结果发现,内生真菌的菌丝体普遍存在于试验材料的叶片、叶鞘、茎节间,内生真菌侵染率大小为:茎节叶鞘叶片,侵染差异在航诱材料与对照间(未经航天诱变的原始材料黔草1号)差异不显著(P0.05);对分离条件优化后,发现从试验材料中分离的内生真菌在pH 7.5,25℃黑暗培养的条件下以添加高羊茅煎煮液的马铃薯琼脂糖培养基PSA的培养效果最佳;在pH 7.5,25℃紫外光照/黑暗交替培养的条件下以添加高羊茅煎煮液的水琼脂培养基WSA的促孢效果最佳。     

施氮对不同氮效率玉米籽粒灌浆的影响

不同的玉米品种在吸收利用氮效率方面存在着显著差异,因此确定不同品种玉米的氮效率很有必要。玉米施氮后的生长效果可以在籽粒灌浆期表现出来。很多学者在对于相同的施氮条件下不同玉米品种间的灌浆特性差异方面做出了不少研究,然而对于不同施氮条件下的灌浆特性差异却鲜有报道。本试验通过观察玉米灌浆动态,旨在确定不同玉米品种氮效率差异的基础上,比较品种间的灌浆特性差异。试验于2013年5月1日—10月7日进行,在大田条件下,以‘屯玉99’、‘潞玉19’、‘先玉335’为材料,对不同供氮水平N0、N1、N2（施纯氮量分别为0、140、210 kg/hm²）下春玉米顶部、中下部籽粒的灌浆动态进行研究。结果表明,‘屯玉99’籽粒鲜重、干重表现为N2＞N1＞N0,‘潞玉19’表现为N1＞N2＞N0,‘先玉335’表现为施氮(N1、N2)＞无氮(N0),其中N1、N2间差别不大。N1条件下的‘潞玉19’发育优势最为显著,其次是N2条件下的‘屯玉99’,N1、N2条件下的‘先玉335’优势最不明显。施氮对顶部籽粒发育的促进作用明显高于中下部籽粒。     

玉米籽粒灌浆速率研究进展

玉米的产量很大程度上受灌浆阶段干物质积累量的影响,灌浆期长短和灌浆速率决定了粒重和产量水平,而灌浆速率受相关基因或QTL以及栽培条件共同调控,表现出复杂的动态变化特征。从灌浆速率的生理代谢、关键酶活性以及遗传与环境等方面概述了玉米籽粒灌浆速率的研究进展。探究玉米籽粒灌浆的分子调控机制将为玉米高产育种提供必要的理论依据。     

19种芽后除草剂对田间杂草的控制和对高羊茅种子生产的影响

为了筛选出适合高羊茅(Festuca arundinacea Schreb)种子生产田施用的除草剂,于2015年在上海闵行地区进行了田间试验。以手工除草和不除草处理为对照,对常用的和近5年内推出的共计19种市售除草剂在除草效果和对高羊茅种子生产的影响上进行了比较。试验结果表明,苯磺隆、谷欢和春杰处理的高羊茅种子产量与手工除草对照的相比没有显著差异,产量下降不到10%,与其他除草剂相比减产幅度较小。该3种药剂处理的种子发芽率均大于90%,与稻欢处理的最高发芽率(96%)相比无显著差异。此外,该3种药剂杀草谱广、见效快,主要防除苦苣菜(Sonchus oleraceus L.)、小飞蓬[Conyza canadensis(L.)Cronq.]、猪殃殃[Galium aparine L.var.tenerum Gren.et(Godr.)Rebb.]、婆婆纳(Veronica didyma Tenore.)、大巢菜(Vicia gigantea Bge.)和葎草[Humulus scandens(Lour.)Merr.]等杂草。因此,苯磺隆、谷欢和春杰是适合在高羊茅种子田施用的安全、高效阔叶杂草除草剂。     

甘肃贝母种子灌浆特性研究

选用5年生甘肃贝母种株,在盛花期挂牌标记开花一致的植株,从开花后第5天开始测定籽粒千粒鲜、干重和含水量,对种子灌浆特性进行研究,旨在为其种子标准化采收提供理论和技术依据。结果表明,甘肃贝母种子千粒鲜重在开花后66d达到最大,随后迅速下降到接近干重的水平。籽粒干重变化的趋势呈“S”型曲线,符合Logistic方程,快增期在花后41～66d,至花后97d灌浆结束。灌浆速率呈“快-慢-快-慢”规律,因降水出现1次低谷,籽粒脱水速率随灌浆进程而加快,含水量持续下降,籽粒含水量下降最快的时期为灌浆高峰结束期。籽粒干重与脱水速率和灌浆持续期均呈极显著正相关,而与籽粒含水量呈极显著负相关。甘肃贝母种子灌浆速率受天气的影响大,籽粒脱水加快、干重趋于稳定是种子成熟的标志,采收期应在花后77～82d(7月底-8月初),种果尚未开裂,种子含水率在40%以下,茎杆尚未完全枯黄时为最佳。