不同放牧强度对人工草地牧草生殖分配及种子重量的影响

不同放牧强度对白三叶,红三叶,鸭茅的生殖分配及种子千粒重影响极显著,一定强度的放牧干扰有利于提高休牧后三叶草的花序密度,但鸭茅花序密度却随放牧强度却随放牧强度的提高而出现明显下降,放牧草地三种牧草种群的生殖分配均低于对照草地,在放牧草地,随放牧强度的提高,白三叶生殖分配逐渐增加,红三叶及鸭茅生殖分配逐渐减少,提高放牧强度后,三叶草千粒重出现递减趋势,而鸭茅却出现递增趋势,在无放牧干扰草地,三叶草种群趋于生产数量较少的大粒种子,在放牧干扰下,趋于生产数量较多的小粒种子;鸭茅种群则出现相反的变化。     

河南若干小麦品种籽粒戊聚糖含量的初步研究

1999-2000年对河南省8个有代表性的小麦品种的戊聚糖进行了测定,不同品种戊聚糖的平均含量变化范围为6%-9%。不同品种和不同生态条件下小麦籽粒戊聚糖含量均有很大差异。5个试点小麦籽粒戊聚糖的平均含量与千粒重,降落值均成负相关关系（r=-0.83,r=-0.31),而与蛋白质的含量却呈正相关关系（r=0.35)。说明戊聚糖含量与生态因素有很大关系,采用Eberhart-Russell模型对小鼠戊聚糖含量的稳定性进行分析。发现豫麦34是戊聚糖含量较理想的品种。     

Phosphorus-copper relationship in wheat

Summary A green-house experiment was conducted to study P–Cu relationship in wheat variety S-308 grown up to maturity. Treatments included five levels, each of P (0, 25, 50, 100 and 250 ppm) and Cu (0, 2.5, 5, 10 and 50 ppm) in all possible combinations. The yield, P and Cu concentration were more with the application of Cu upto 5 ppm with P, and P upto 50 ppm with Cu, over P alone and Cu alone, respectively. Application of 50 ppm Cu adversely affected yield and P concentration and 250 ppm P adversely affected yield and Cu concentration. Application of affected nutrient counteracted to a great extent the adverse effect of the other nutrient. The low levels of P and Cu were essential for better plant growth and efficient utilization of both the nutrients and antagonism was noted only when one of the nutrients was applied in high quantities.Contribution from the Department of Soils, Haryana Agric. Univ., Hissar-India.     

Can wheat yield be assessed by early measurements of Normalized Difference Vegetation Index?

An early prediction of crop biomass at maturity and yield is important in different circumstances. The use of spectral reflectance indices, such as the Normalized Difference Vegetation Index (NDVI), has been proposed as a fast, nondestructive way of estimating crop growth capacity. In this study, we examined whether NDVI assessment relatively early in the crop cycle may be useful for predicting final biomass and yield in wheat. To that end, NDVI was measured and biomass quantified regularly from tillering to maturity for six different wheat genotypes grown under a contrasting range of N and water availabilities. In addition, final biomass and yield were measured at maturity. In line with expectations from the literature, we found that NDVI at milk-grain stage was well correlated to final yield and biomass. However, it was also observed that NDVI at the onset of stem elongation was also reasonably correlated to both attributes. Because crop growth in wheat from the end of tillering to anthesis is related to the determination of grain number and yield, we propose the use of NDVI at the onset of stem elongation as a complementary criterion for establishing the required late crop management (N fertilisation, irrigation) practices.     

耕作播种方式对稻茬小麦生长和养分吸收利用的影响

2016—2018年,在四川省广汉市分析了深旋耕播种(DRT)、浅旋耕播种(SRT)和免耕带旋播种(NT)3种耕播方式对稻茬小麦生长和养分吸收利用的影响。结果表明:与DRT相比,SRT和NT处理提高了小麦分蘖、成穗能力。2016—2017年,处理间产量无显著差异;2017—2018年,NT处理产量显著高于DRT,增幅10.9%。处理间干物质积累的差异主要在苗期。NT处理下植株对氮的吸收量高于DRT,平均增幅9.9%,而氮收获指数DRT高于NT;各处理植株磷吸收量差异不显著;NT处理对钾的吸收量显著高于DRT。与传统的深旋耕播种方式相比,免耕带旋播种技术是提高稻茬小麦产量和养分吸收的有效途径。     

Bt毒素在三种矿物表面的吸附与解吸

研究了Bt库斯塔克亚种(kurstaki）毒素（65 kDa）在高岭土、针铁矿和氧化硅表面的吸附和解吸特性.结果表明：在磷酸盐缓冲体系（pH 8）中,3种矿物的等温吸附曲线均符合Langmuir方程（R²>0.9661）,它们对Bt毒素的吸附顺序为：针铁矿﹥高岭土﹥二氧化硅.矿物对Bt毒素的吸附1 h就基本达到了吸附平衡.在pH 6～8范围内,针铁矿、高岭土和二氧化硅对Bt毒素的吸附量随pH值的升高而降低.10 ℃～50 ℃范围内,针铁矿和氧化硅对Bt毒素吸附量随温度升高有所下降（8.39％和47.06％）,高岭土对Bt毒素吸附则略有升高（5.91％）.红外光谱分析显示,Bt毒素被矿物吸附后结构仅有微小变化.被矿物吸附的Bt毒素不易被去离子水解吸,水洗3次总解吸率为28.48%～42.04%.     

Efficacy of the biocontrol yeast Pichia anomala during long-term storage of moist feed grain under different oxygen and carbon dioxide regimens

The yeast Pichia anomala inhibits the spoilage mold Penicillium roqueforti in laboratory experiments with high-moisture wheat in malfunctioning airtight storage. The ability of P. anomala to prevent mold growth during 14 months of grain storage was evaluated in outdoor silos with different air permeabilities. Freshly harvested wheat in 160-kg portions was inoculated with 10(2) colony-forming units (cfu) g(-1) P. roqueforti, alone or together with 10(4) cfu g(-1) P. anomala. During the first month P. anomala increased to about 10(6) cfu g(-1) in the treated silos to reach 10(7) cfu g (-1) after 9 months. Naturally occurring P. anomala in the untreated silos increased from 10(2) to about 10(3) cfu g(-1) during the first month and reached the same level as the treated silos after 9 months. Oxygen levels were reduced below the detection limit within 1 day, while carbon dioxide levels increased to 80-90% during the first month. P. roqueforti did not grow in wheat treated with P. anomala, regardless of silo permeability, but had increased to 10(5) cfu g(-1) in the untreated silos after 14 months of storage.     

Disease in wheat genotypes naturally infected with Gaeumannomyces graminis var. tritici

Wheat genotypes consisting of seven homozygous lines and 40 segregate families were studied at two sites naturally infested with the take-all pathogen, Gaeumannomyces graminis var. tritici. The numbers of seminal and coronal roots infected with G. graminis and other root pathogens were recorded. The genotypes differed in infection with G. graminis, with little evidence of genotype × environment interactions. The incidence of G. graminis and Rhizoctonia solani was negatively associated, but the association did not greatly influence differences between wheats in infection with G. graminis. The distribution of R. solani was negatively associated with the severity of take-all at only one site. Of symptoms of infection with G. graminis, wheat genotypes differed most in incidence of deadheads, but differences were not consistent over environments, and were associated with earliness of maturity. Wheats differed more in expression of disease than in infection with G. graminis. The course of disease was deduced from associations between the incidence of pathogens and components of plant growth and yield. G. graminis was the dominant pathogen at both sites, and caused a yield loss of 0–15% at one site, and an average 62% loss at the other. More components of yield were affected where disease was most severe.     

杂交粳稻及其亲本千粒重与产量、品质的相关性

为了探明杂交粳稻及其亲本千粒重与产量、品质的关系,以4个千粒重介于23.1~28.0 g之间的BT型不育系和24个千粒重介于18.1~32.0 g之间的三系粳稻恢复系,采用p×q不完全双列杂交(NCⅡ)设计,配制96个杂交组合为试验材料,对F1千粒重优势表现、F1千粒重与亲本千粒重及其与产量、品质性状间的相关性进行分析,确定高产优质兼顾的杂交粳稻的千粒重范围。结果表明:(1)56.3%的杂交组合千粒重超过其双亲平均值,19.8%的杂交组合千粒重表现正向超亲优势;(2)F1千粒重与母本千粒重、父本千粒重、双亲千粒重平均值的相关性均达极显著水平(r=0.33**、0.71**、0.78**),且恢复系千粒重对杂种的影响大于不育系;(3)F1千粒重、父本千粒重及双亲千粒重平均值与组合单株产量的相关性均达极显著水平(r=0.55**、0.47**、0.51**),母本千粒重与组合单株产量相关不显著;(4)F1千粒重、父本千粒重与糙米率、精米率、整精米率、垩白粒率、粒长、粒宽均呈极显著正相关,与透明度呈显著正相关,母本千粒重与垩白粒率、垩白度、粒长均呈极显著正相关,与粒宽呈显著正相关;(5)杂交粳稻育种中具有高产优质兼顾的F1千粒重范围应在25.1~27.0 g之间。     

GW3-1和IND109标记对普通小麦粒重的QTL定位分析

应用一个由115个系组成的W7984/Opata85的重组自交系(RIL)群体,建立了一个由394个(292个RFLP、94个SSR和8个特殊的基因杂交探针)DNA分子标记组成的遗传连锁图,对小麦千粒重进行了单个标记的回归分析和复合区间作图的QTL定位,在单个标记的回归分析中检测到11个千粒重的QTLs(P<0.01);复合区间作图分析结果表明,其中4个标记bcd348a、GW3-1、IND109和Rz2的遗传效应较大,其贡献率分别为9.1%、19.0%、8.07%和8.14%,分别位于小麦的2BS、4AL、5BL和7DS上,特别是在水稻第3条染色体上控制籽粒大小的GW3-1和IND109分别位于小麦4A和5B染色体的长臂端.研究结果对小麦应用分子标记辅助选择或分子克隆基因有重要的参考价值.     

Plant husbandry and vegetation of early medieval Douai,northern France

This paper describes the results of the archaeobotanical examination of early medieval occupation deposits (8th to 11th centuries A.D.) at Douai, northern France. Carbonized as well as waterlogged seeds and fruits were recovered in great numbers. In addition to the macrofossil analyses, a palynological examination of occupation deposits was carried out. Bread wheat (Triticum aestivum) was the most common cereal, followed by rye (Secale cereale). Common oat (Avena sativa) and hulled barley (Hordeum vulgare) must have played a fairly modest role. In addition to cereals, field pea (Pisum sativum) was an important crop plant. Four types of plum (Prunus domestica) fruitstones are distinguished. Sweet cherry (Prunus avium) as well as sour cherry (P. cerasus) were cultivated. Other cultivated fruit trees included peach (Prunus persica) and medlar (Mespilus germanica). Sloe (Prunus spinosa) fruits, including those of the var. macrocarpa, were gathered from the wild. The palynological data suggest that the Douai area had virtually been cleared of forest. A comparison between pollen and seed proportions points to serious discrepancies between the macrofossil and microfossil plant records. Weeds of arable land (Secalietea, Polygono-Chenopodietalia) and vegetations of ruderal habitats (Sisymbrietalia, Artemisietalia vulgaris) are well represented. Molinietalia vegetations in the valley of the Scarpe river were probably exploited as hay meadows; good pasture land was provided by the Arrhenateretalia grasslands.     

大麦胚乳细胞增殖动态及其与粒重的关系

大麦籽粒胚乳细胞数在花后17 d左右就基本决定,增殖动态可用Richards曲线方程拟合,决定系数0.9900以上,达极显著水平.籽粒胚乳细胞数目、单个细胞重量与粒重均存在极显著正相关,r值分别为0.9019**和0.9409**.籽粒胚乳细胞数对粒重影响最大,单个胚乳细胞重次之,胚乳细胞数的多少是决定粒重的主要原因.     

不同小麦进化材料生育后期光合特性和产量

以二倍体野生一粒小麦(Triticum boeoticum)、栽培一粒小麦(T. monococcum)、节节麦(Aegilops tauschii)和黑麦(Secale cereale)、四倍体野生二粒小麦(T. dicoccoides)、栽培二粒小麦(T. dicoccum)、硬粒小麦(T. durum)、六倍体普通小麦(T. aestivum)‘扬麦9号’和‘扬麦158’及八倍体小黑麦(Triticale)为材料,采用盆栽试验研究了不同小麦进化材料生育后期旗叶光合特性的演变及产量的差异。结果表明,与六倍体普通小麦和八倍体小黑麦相比,二倍体和四倍体材料在开花前具有较高的光合速率(P_n)、气孔导度(G_s)、最大光能转换效率(F_v/F_m)和实际光化学效率(Φ_PSⅡ)。开花以后,二倍体和四倍体材料受非气孔因素的影响,光合能力下降较快;除黑麦外,旗叶光合速率在开花10 d后都低于普通小麦和小黑麦,胞间CO₂浓度(C_i)迅速增加,F_v/F_m、Φ_PSⅡ和叶绿素含量快速下降。二倍体和四倍体材料开花前单株总叶面积和旗叶叶面积较大,花后下降迅速,功能期短;单株穗数也较多,但穗粒数、千粒重、产量和收获指数却显著低于普通小麦。因此,小麦长期进化过程中,普通小麦花后较高的光合能力及较长的光合持续期是提高千粒重,进而提高产量的重要生理基础。