小麦品种产量与产量因素通径分析

通过对９４个不同品种小麦在渭北地区干旱条件下的试验数据,分类建立小麦产量与产量因素的回归关系,并做了通径分析。结果表明,在分类小麦的关系中,穗粒数对产量的总影响和直接影响都最大。     

小麦单籽粒性状与品质的关系

目前测定小麦单籽粒品质的方法有单籽粒谷物品质测定法和谷蛋白溶涨指数法(SIG)。为了揭示单籽粒品质检测的作用,选用16个小麦品种(系)进行单籽粒性状的研究,结果表明,品种内单籽粒硬度、籽粒直径、单籽粒重量及SIG的变异较大,水分含量变异不大。单籽粒品质指标硬度、粒重、粒径及SIG与磨粉品质、面团流变学特性、蛋白质品质、籽粒品质部分指标呈显著或极显著相关,这些指标对于预测磨粉品质、早代株系品质筛选及食品品质具有快速、方法简单及预测能力强的优点。将单籽粒谷物品质测定参数及SIG相结合,可以有效地进行小麦育种后代筛选及品质预测。     

小麦轮回选择的初步实践

利用太谷核不育小麦,开展以抗锈和矮秆丰产为主要目标的轮回选择,选择压分别为5.6%和4.7%.抗锈群通过一轮混合选择,条锈病反应型0—1级的抗病株率和严重度25%以下的轻病株率较基础群体分别提高12.5%和5.1%.矮秆丰产群采用两种轮选方案.经两轮选择看出,改良半姐妹法其群体的株高比基础群体明显降低6.2厘米,其余性状有向选择目标集中的趋势;混合选择法其群体除穗粒数外,其余性状进展趋势与上相同.     

Pb在小麦植株内吸收、分配和累积的研究

通过大田试验，研究了Pb在小麦植株中的吸收、分配和累积的动态变化规律。结果表明，在小麦整个生长过程中，不同部位Pb含量和Pb累积量随着时间的推移而变化，但从总体上看是根〉茎〉子粒。在灌浆末期，各部位Pb含量从大到小依次为：根〉废弃物〉叶〉茎〉叶鞘〉颖片〉穗轴〉子粒，地上各部位Pb累积量从大到小依次为：废弃物〉茎〉叶鞘〉颖片〉叶〉子粒〉穗轴。从结果还可以看出，小麦植株中较易富集Pb的部位是根、废弃物、茎和叶，而子粒中Pb含量和累积量均比较低。小麦在生殖生长阶段的Pb吸收量大于营养生长阶段；拔节一抽穗期和灌浆初期一灌浆中期Pb吸收量及吸收速率显著高于其他时期。     

Regional phenotypic diversity of Puccinia triticina and wheat host resistance in western Europe, 1995

Pathogenicity data from surveys of Puccinia triticina (formerly P. recondita f. sp. tritici) conducted in western Europe in 1995 were analysed to compare the structure of regional populations of the pathogen. Many of the populations differed in phenotypic diversity and pathotypic composition, even though they occurred within a single epidemiological unit, suggesting that local factors may influence the establishment and propagation of individual pathotypes in the regional populations. Neighbouring regions were more similar than distant regions, and all regions shared at least one pathotype, except populations in northern Italy and Scotland. A high degree of similarity was found between populations in northern France and Great Britain, providing strong evidence of free movement of inoculum between these regions. Resistance genes were postulated for a selection of 91 wheat cultivars, representing those most commonly grown in western Europe in 1995. Thirteen cultivars lacked detectable seedling resistance genes and the remaining 78 possessed from one to three resistance genes; those detected were Lr1, Lr3a, Lr10, Lr13, Lr14a, Lr17b, Lr20, Lr26 and Lr37. The most commonly detected resistance gene was Lr13, which was present singly or in combination with other resistance genes in 48 cultivars (53%). The gene Lr14a was detected in 18 cultivars, Lr26 was present in 16 cultivars. The role of host selection in the composition of the regional populations of P. triticina in western Europe in 1995 was difficult to assess on the basis of the results obtained, since virulence data were not available for Lr13 and Lr14a. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of solid state fermentation by Enterococcus faecalis M2 on antioxidant and nutritional properties of wheat bran

Wheat bran is the main by-product during wheat flour processing. Although wheat bran is rich in the bioactive compounds and antioxidant capacity, it is not widely utilized in its natural state. To improve the antioxidant and nutritional properties of wheat bran, a dominant strain, Enterococcus faecalis M2, was screened from lactic acid bacteria (LAB) isolated from various foods. Following solid state fermentation, the soluble dietary fiber content of wheat bran nearly quadrupled compared to the raw material. Total proportion of phenols, flavonoids, alkylresorcinols, along with the antioxidant capacity and free radical scavenging rate were significantly improved, particularly the ferulic acid content increased by 5.5 times. Additionally, the free amino acid content increased with degradation of wheat bran protein, whereas the level of anti-nutrient phytic acid decreased. The results of this study could provide an effective method for biological modification of wheat bran, which further enhance the health benefit and utilization of bran.     

中期种质库贮藏下真空和非真空包装普通小麦种子的衰老特性及寿命差异

为了解低温中期种质库[(−2±2)℃]贮藏下普通小麦种子的衰老或存活特性及贮藏前环境相同的同一基因型种子在真空密封和非真空包装保存中的种子寿命差异,探讨低温中期种质库延长种子寿命的适宜种子包装方式,分析了两种包装的89份普通小麦种子保存11年的存活分布、衰退率(1/σ)、初始质量(K_i)、平均寿命(P₅₀)和贮藏寿命(log σ)。结果表明, 两种包装89份种子的衰老或存活频率均符合正态分布,但是部分基因型种子的衰退率和寿命因不同包装而出现差异。贮藏前环境及种子水分相同的同一基因型种子,真空密封保存较非真空贮藏显著衰老的比例小、程度轻,因而真空密封贮藏更利于维持种子寿命。虽然真空密封保存的种子较非真空贮藏的种子K_i值高,但并不支持K_i值是种子初始质量或潜在种子寿命的假设。     

Long-term continuous cropping in the Pacific Northwest: Tillage and fertilizer effects on winter wheat, spring wheat, and spring barley production

Conventional tillage winter wheat (Triticum aestivum) (WW)–summer fallow reduces soil productivity and increases soil erosion. Conservation tillage management, together with intensive cropping may have the potential to reverse these sustainability concerns. The objective of this study was to determine the effects of conventional tillage (CT) and no-tillage (NT) systems on grain yield of long-term annual cropping of monoculture WW, spring wheat (SW), and spring barley (Hordeum vulgare) (SB) grown with or without fertilizer, in the Pacific Northwest region of the USA. In unfertilized crops, grain yield of WW, SW, and SB was 15%, 25%, and 50% higher, respectively, in CT than in NT plots, an indication of the involvement of yield limiting factors under the NT cropping system. When fertilized, there were no significant differences in grain yield of WW. Yields of SW and SB, however, remained 21% and 15% higher, respectively, in CT than in NT, an indication that factors other than fertility were involved. These results suggest that in order for NT management to be widely adopted by area growers, the yield-limiting factors need to be addressed.     

三种数学模型模拟不同播期小麦籽粒灌浆过程的比较分析

为比较分析Logistic、Richards和三次多项式(Cubic)3种小麦籽粒灌浆模型的特点,用其分别对4个小麦品种(济麦44、品育8012、周麦36和晋麦84)在4个播期下的籽粒灌浆过程进行拟合。结果表明,不同播期小麦籽粒灌浆过程用三种模型均可拟合,各模型方程的决定系数均在0.98以上,且达极显著水平,Cubic和Richards模型拟合效果优于Logistic模型;通过Cubic模型模拟的灌浆起始期较观测值晚0.58～6.65 d, 10月12日播期起始灌浆日期模拟值与观测值最接近;在本试验条件下,Logistic模型可以假定粒重达理论最大粒重的2.76%左右时为灌浆起始期(开花期);Richard模型中,播期对起始粒重比例(灌浆起始期粒重/理论最大粒重)有显著影响,第一、第二播期(10月12日、10月20日)的超始粒重比例显著低于第三、第四播期(10月28日、11月5日);三种模型理论最大粒重在品种和播期间的规律与灌浆终止粒重一致;Cubic模型模拟的理论最大粒重与灌浆终止粒重最接近,终止粒重比例(灌浆终止粒重/理论最大粒重)平均值达97.84%;Logistic与Richa...     

小麦禾谷镰刀菌毒素抗性系的筛选及抗性特性

以稳定生长的小麦（抗盐０３×Ｎｏ１８）Ｆ１花药愈伤组织为材料，小麦强致病禾谷镰刀菌的粗毒素为选择剂，进行抗毒素变异细胞系的离体筛选。结果从多步正筛选系统和一步正筛选系统分别获得抗性变异细胞系ＫＮｒ－ａ和ＫＮｒ－ｂ．抗性系的毒素抗性具有显著提高，且其细胞膜透性、硝酸还原酶活性、苯丙氨酸解氨酶活性、游离氨基酸组成均发生了明显变化。据此提出了细胞水平上禾谷镰刀菌毒素作用的机理及抗性变异细胞系对毒素表现出一定抗性的可能原因