冬小麦品种粒重叶比的遗传研究

本研究采用Griffing方法Ⅰ,利用6 × 6完全双列杂交,对6个不同类型的冬小麦品种粒重叶比的遗传进行了初步分析.结果表明粒重叶比的一般配合力(GCA)效应,特殊配合力(SCA)效应和反交(R)效应,均达到极显著水平,其均方比为1.94650.67001;粒重叶比的遗传以加性基因效应占优势,但反交效应和非加性基因效应也不可忽视;粒重叶比的广义遗传力(hB2)为97.79%,狭义遗传力(hN2)为58.53%.河农2552是较为理想的育种亲本.     

断根对冬小麦竞争能力与产量的影响

 采用简化的deWit替代系列法研究了盆栽冬小麦‘长武135’（Triticum aestivum cv. Changwu 135）在拔节初期断根对冬小麦根冠关系、竞争能力及其与产量性状的关系。无论干旱或湿润,单栽条件下断根降低了小麦的根冠比,在混栽条件下,断根小麦的相对穗重和相对地上部生物量均显著低于未断根小麦,说明断根降低了小麦的竞争能力。根冠比越大竞争能力越强,即作物的竞争能力与根冠比存在正相关关系。单栽湿润条件,断根降低了小麦的穗重和籽粒产量,而在中等干旱条件下,断根小麦穗重和籽粒产量高于未断根小麦 。说明在水资源充分的条件下,较高的作物个体竞争能力则具有较高的生产能力,而在水资源有限的情况下,降低作物个体竞争能力反而提高了群体籽粒产量。     

Relationships between carbon isotope discrimination, dry matter production, and harvest index in durum wheat

Carbon isotope discrimination has been proposed as a criterion for the indirect selection to improve transpiration efficiency and grain yield in bread wheat and barley. Less attention has been devoted to durumwheat (Triticum durumDesf.) despite its economic importance in the Mediterranean basin. The Δ genetic variation and its relationships to dry matter production and harvest index in durum wheat were investigated in this study. For this purpose, field experiments were conducted on 144 durum wheat accessions under Mediterranean conditions (South of France) during three consecutive years with contrasting climatic conditions. Grain yield, above-ground biomass, harvest index, and carbon isotope discrimination of flag leaf and kernel were measured. Differences between years, noted for both leaf and kernel carbon isotope discrimination, were probably related to the variation in water availability from year to year. A large genotypic variation was also noticed for both leaf and kernel carbon isotope discrimination. The two traits were found to be positively correlated with grain yield within and across years, which confirms the interest in carbon isotope discrimination for selection for grain yield improvement under Mediterranean conditions. Both kernel and leaf carbon isotope discrimination correlated better with harvest index than with grain yield, suggesting that carbon isotope discrimination could reflect the efficiency of carbon partitioning to the kernel. The lack of correlation between leaf carbon isotope discrimination and both harvest index and grain yield in favourable water conditions (1996) was probably due to the difference in water availability between the period until flag leaves sampling (favourable conditions) and the strong water stress which accompanied the grain filling. Kernel carbon isotope discrimination correlated better with both harvest index and grain yield than did leaf carbon isotope discrimination. Moreover, a higher broad-sense heritability was obtained for kernel carbon isotope discrimination than for leaf carbon isotope discrimination. As a result, kernel carbon isotope discrimination appeared to be a better predictive criterion for efficiency of the carbon partitioning to the kernel (harvest index), and hence for grain yield, than did flag leaf carbon isotope discrimination.     

Effects of nutrient solution zinc activity on net uptake,translocation, and root export of cadmium and zinc by separated sections of intact durum wheat (Triticum turgidum L. var durum) seedling roots

Cd accumulation in durum wheat presents a potential health risk to consumers. In an effort to understand the physiological mechanisms involved with Cd accumulation, this study examined the effects of Zn on Cd root uptake and phloem translocation in a split– root system. Durum wheat seedlings were grown in chelate-buffered nutrient solution with intact root systems divided into two sections. Each root section grew in a separate 1 l pot, one of which contained 0.2 μM CdSO₄. In addition, each two-pot system contained ZnSO₄ in the following combinations (in μm) (for -cd root system: +cd root system): 1:1, 1:10, 10:1,10:10, 1:19, and 19:1. Harvested plant material was analyzed for Cd and Zn. In addition, rates of Cd and Zn net uptake, translocation to the shoot, and root export (translocation from one root segment to the other) between days 8 and 22 were calculated. Results show that Zn was not translocated from one root section to its connected root section. Uptake rates of Cd increased as solution Zn concentrations increased. Cd translocation from one root section to the other decreased significantly when the Zn concentration in either pot was greater than 1 μM. These results show the potential of Zn to inhibit movement of Cd via the phloem, and suggests that providing adequate Zn levels may limit phloem loading of Cd into wheat grain. Increasing the rhizosphere activity of Zn²⁺ in Cd-containing soils may therefore result in reduced Cd accumulation in grain even while net Cd uptake is slightly enhanced. This revised version was published online in June 2006 with corrections to the Cover Date.     

不同抗旱性冬小麦根系时空分布与产量的关系

为明确不同抗旱性冬小麦品种(Triticum aestivum L.)根系时空分布及其与产量的关系,以抗旱性品种长武134、长旱58和干旱敏感性品种小偃22、西农979为材料,采用根箱试验研究干旱胁迫和充分供水条件下4个品种在拔节期、开花期和成熟期根系总生物量、总根长密度、根系在表层(0—20 cm)和深层(20 cm以下)土壤中的垂直分布、动态变化及其对产量的影响。结果表明,干旱胁迫下抗旱性品种产量显著高于干旱敏感性品种,其中长旱58产量最高,西农979最低;充分供水条件下,西农979产量最高,长武134最低,长旱58与小偃22之间没有差异。相关分析表明,产量与各生育时期根系性状均有显著关系。多元逐步回归分析的结果显示,干旱胁迫和充分供水条件下,拔节期深层根生物量对产量有正效应,而成熟期总根长密度对产量表现为负效应。通径分析表明,干旱胁迫下,根系性状对产量的直接贡献大小为开花期总根长密度(|0.54|)拔节期深层根生物量(|0.36|)成熟期总根长密度(|-0.31|);充分供水时,成熟期总根长密度(|-1.56|)拔节期深层根生物量(|0.83|)。研究表明,减少成熟期总根长密度,增加拔节期深层根生物量对抗旱性及干旱敏感性冬小麦品种产量均有显著的正效应,增加开花期根长密度有利于提高抗旱性冬小麦产量。     

水氮互作对固定道垄作栽培春小麦根系生长及产量的影响

为探讨固定道小麦栽培方式下适宜的水氮组合,以低水1200 (W₁)、中水2400 (W₂)、高水3600 m³·hm^-2 (W₃)为主处理,0 (N₀)、低氮90(N₁)、中氮180 (N₂)、高氮270 kg·hm^-2 (N₃)为副处理,采用裂区设计,对固定道垄作栽培方式下水氮互作对春小麦根系生长及产量的影响进行了研究.结果表明:水氮互作能显著影响春小麦根干质量密度(RWD),RWD随着小麦生育期的进程表现为先增大后减小的趋势,在灌浆期达最大;RWD对施氮量的响应取决于灌溉量,在W₁下,RWD在N₁处理下最大,在W₂下,RWD随着施氮量的增加在N₂处理下最大,在W₃下,RWD随着施氮量的增加在N₃ 处理下最大;不同灌溉处理下RWD表现为W₂>W₃>W₁;施氮与灌水显著影响RWD,表现为灌水>氮肥>水氮互作,在W₂N₂处理下最大.根冠比随着灌水量与施氮量的增加逐渐减小,在W₁N₀处理下根冠比最大;85%以上的小麦根系分布于0～40 cm土层,产量与0～40 cm土层RWD呈显著抛物线回归关系,与40～60 cm土层RWD呈显著线性正回归关系.W₂灌溉条件可以促进小麦根系向中下层(40～60 cm)分布;灌水施氮能显著影响春小麦籽粒产量与生物产量,生物产量随着施氮量和灌水量的增加而增加,籽粒产量在W₂N₂最大;灌水生产力随灌水量的增加逐渐降低,氮肥农学利用率随施氮量的增加而减小.因此,在固定道垄作栽培方式下,施肥量与灌水量控制在N₂ (180 kg·hm^-2)与W₂(2400 m³·hm^-2)条件下有利于促进根系生长,进而提高春小麦籽粒产量及水氮利用效率,是河西灌区固定道小麦栽培方式下适宜的水氮组合.     

Rooting patterns in near-isogenic lines of spring wheat for dwarfism

The effects of Rht alleles on root growth and distribution in isogenic lines of spring wheat (Triticum aestivum L.) are described under different environmental conditions. Above-ground biomass, root length, root dry-weight and their distribution along the soil profile were measured by destructive sampling for growth of aerial biomass and extraction of soil cores containing roots. Field experiments were conducted under non-limiting water and nutritional conditions during two consecutive years, using an early and a late sowing date each year.Dwarfing genes significantly reduced plant height and above-ground biomass at anthesis. In addition, stem mass ratio also was reduced with increases in the allelic dosage. Conversely, total root length and root dry-weight per unit area at anthesis were increased with decreased plant height, therefore, root mass ratio tended to be negatively correlated with plant height. Differences in distribution of root length and root dry-weight through the soil profile among lines were largely confined to the upper soil layers (i.e. the top 30 cm).Differences in root dry-weight were more important than in root length, so that the dwarf line had the highest root mass per unit root length. Furthermore, a significant positive correlation between the root mass ratio and stem mass per unit stem length was found. It is suggested that increases in root mass per unit root length associated with Rht alleles are evidencing a surplus of photoassimilates during stem elongation which are used for thickening the roots due to the lack of alternative sinks. Agronomic implications of this effect are discussed.     

Deoxynivalenol (DON) in hartweizen

Deoxynivalenol (DON) in Durum Wheat High contamination levels of deoxynivalenol (DON) were found during an investigation of noodles in 2001 and initiated an additional survey of Durum wheat used as raw material for these products. Analyses of 53 samples of Durum wheat by HPLC revealed 89% positives and a median concentration of 790 ug/kg, which clearly exceeded the EU action level of 500 μg/kg. Based on these findings, producers increased quality controls on Durum wheat. In 2002 a total of 60 samples were analysed and 85% positives found. The median, however, lay at 215 μg/kg, below a probable maximum level of 500 μg/kg and demonstrated the positive efforts of food producers to decrease the contamination levels of DON in pasta products.     

试论麦类作物非水力根信号与生活史对策

从植物非水力根信号的生理调节作用和生活史进化解度看,在水分亏缺条件下,自然选择会导致植物产生大量根系以增加对水分的竞争能力,而浅根系则可在干旱来临时,以快速反应的根信号来调节和平衡植株水分状况,度过干旱时期。但是,自然选择压力下的植物特征往往不利于作物籽粒产量这一种群水平上的属性的改善。作物产量的提高过程是一个不断加强的人工选择过程。在作物生产中,作物水环境得到了改善,强大的多年生竞争者基本消失,     

灌溉频次和时期对冬小麦籽粒产量及品质特性的影响

为探讨我国北方地区冬小麦的节水灌溉模式,2006—2008年,在中国科学院栾城农业生态系统试验站,以冬小麦品种科农9204为试验材料,在总灌溉量为120mm的条件下,研究了灌溉次数和灌溉时期对籽粒产量、水分利用效率(WUE)、籽粒蛋白质含量以及相关主要品质特性的影响。结果表明,拔节期、抽穗期和灌浆期一次灌溉分别有利于产量、干物质积累量和千粒重的形成或提高;两次灌溉处理中,以拔节和抽穗期各灌60mm处理籽粒产量最高,籽粒蛋白质产量有随灌溉时期后移而降低的趋势;冬小麦生育期间随灌溉次数增多和灌溉时期后移,湿面筋含量、面团形成时间、面团稳定时间等均显著降低。综合考虑冬小麦的籽粒产量、WUE、营养品质和加工品质,在总灌溉量为120mm的条件下,以拔节和抽穗期各灌溉60mm为宜。     

Soil redox-pH stability of arsenic species and its influence on arsenic uptake by rice

Although the auger method has been reported to be simple and superior to other methods of determination of roots, a standard procedure of determining roots with the same is lacking. In a bid to standardize the auger method for studying wheat root distribution; we sampled roots with 5, 7.5 and 10 cm ID augers on the row and midway between rows down to 180 cm. The suitability of a sampling scheme was adjudged from bias between observed and actual root length densities (RLD). The actual density in a layer was obtained by integrating the equation fitted to the average of root density data horizontally between 0 and 11 cm, because for 22 cm apart rows of wheat the representative half of the unit soil strip was 11 cm from the row; and assumed actual RLD was the average of horizontal distribution of RLD in a particular layer. Single site sampling on the row or between rows gave the maximum bias. Average of two sites viz. on the row and midway between rows with 10 cm ID auger and 7.5 cm ID auger or at three sites with 5 cm ID auger (additional site midway between the earlier two) gave the best estimates in that order.     

春小麦竞争能力与产量的关系

采用deWit替代系列实验确定了4个春小麦品种混播时的竞争能力与单播产量之间的关系。4个春小麦品种竞争能力由强到弱的排序依次为定西-24、和尚头、陇春-8139和高原-602。各品种单播时产量由高到低的排序依次为现代品种定西-24、陇春-8139、高原-602与地方品种和尚头。该结果表明,以优化个体适合度为目标的自然选择,导致个体竞争能力提高、繁殖分配下降,因而产生‘生长冗余’及群体表现下降。现代小麦育种通过降低竞争能力,剔除生长冗余,可以提高小麦单位面积产量(如地方品种和尚头与现代品种高原-602和陇春-8139的比较)。然而,如果现代小麦育种可以同时提高收获指数和地上生物量(如现代品种定西-24与陇春-8139和高原-602的比较),那么具有相对较高竞争能力的品种仍然可望获得较高产量,其前提是具有较高竞争能力的育成品种有着较高的收获指数。因此,春小麦品种的个体竞争能力并不必然地与产量相关,当选育的品种可以使竞争能力与收获指数同步提高,或者伴随着竞争能力的提高,收获指数具有更大幅度的提高,仍然可以获得高产。半干旱地区作物育种应集中于收获指数和地上生物量的同时提高。     

不同畦长灌溉对小麦耗水特性及产量的影响

在2009-2010和2010-2011年小麦生长季,设置10、20、40、60、80和100 m 6个畦田长度,研究不同畦长对小麦耗水特性及产量的影响.结果表明： ≤80 m畦长处理下,随畦长的增加,灌水量逐渐增加,灌水量占总耗水量的比例增加,土壤贮水消耗量减少,小麦拔节至开花期的耗水量和生长季总耗水量均减少,开花期0～200 cm各土层土壤含水量增加,土壤供水能力提高,籽粒产量和水分利用效率逐渐提高.与80 m畦长处理相比,<80 m畦长处理的灌水量少,上层土壤含水量低,促使小麦吸收更多的深层贮水,总耗水量增加,不利于节水;而100 m畦长处理的灌水量、土壤贮水消耗量和总耗水量均增加,由于一次性灌水量过多且灌溉水分布不均匀,导致小麦千粒重降低,籽粒产量和水分利用效率显著下降,也不利于节水高产.     

微喷带长宽对不同区段麦田水分和小麦旗叶叶绿素荧光特性的影响

2014—2015和2015—2016年小麦生长季,设置微喷带长宽组合处理:带宽65 mm下设置带长60 m (T₁)、80 m (T₂)和100 m (T₃)处理,带宽80 mm下设置带长60 m (T₄)、80 m (T₅)和100 m (T₆)处理,研究不同组合对麦畦各区段(沿微喷带铺设方向分为D₁至D₆)水分和旗叶叶绿素荧光特性的影响.结果表明: 拔节期灌溉,带宽65 mm下喷洒均匀系数为T₁>T₂、T₃,带宽80 mm下为T₄、T₅>T₆;开花期灌溉,带宽65 mm下为T₁>T₂>T₃,带宽80 mm下为T₄>T₅>T₆.65 mm带宽下,T₁开花期灌溉后各区段0～40 cm土层平均土壤相对含水量,以及花后20和30 d旗叶实际光化学效率(Φ_PSII)、非光化学猝灭系数(NPQ)、电子传递效率(ETR)和籽粒产量均无显著差异;T₂为D₁、D₂>D₃>D₄>D₅;T₃为D₁、D₂>D₃>D₄>D₅、D₆.各区段花后20和30 d旗叶Φ_PSII、NPQ、ETR以及成熟期各区段干物质积累量为T₁>T₂、T₃.80 mm带宽下,T₄开花期灌溉后各区段0～40 cm土层平均土壤相对含水量,以及花后20和30 d旗叶Φ_PSII、NPQ、ETR和籽粒产量无显著差异,T₅为D₁、D₂、D₃>D₄、D₅;T₆为D₁、D₂、D₃>D₄>D₅>D₆.各区段花后20和30 d旗叶Φ_PSII、NPQ、ETR以及成熟期各区段干物质积累量为T₄、T₅>T₆.籽粒产量和水分利用效率为T₁、T₄、T₅>T₂、T₃、T₆,灌溉效益T₁、T₄优于T₅处理.本试验条件下,带宽65 mm下T₁和带宽80 mm下T₄为节水高产的最优处理,T₅为较优处理.     

Genetic analysis of agronomic characters in chickpea. II. Estimates of genetic variances from line × tester mating designs

Summary Thirty line x tester experiments involving diverse chickpea (Cicer arietinum L.) germplasm were conducted over 8 years and three locations to determine the nature of the genetic variance for grain yield and related characters, and the effects of generation and environment on these genetic parameters. Days-to-flowering, 100-seed mass, and seeds per pod were predominantly under the control of additive genetic variance, while both additive and non-additive genetic components of variance were important for days-to-maturity, plant height, primary and secondary branches, pods per plant, and seed yield. The F₁ and F₂ generations were found equally useful in estimating the genetic variances for different characters because the generation did not significantly interact with genetic parameters in the majority of cases. Sites or seasons, on the other hand, showed significant interaction with genetic components of variances; additive variance showed a larger interaction with environments than non-additive variance. This indicated the importance of more than one site and/ or season for unbiased estimation of the genetic components of variance. The results were compared with previous findings from diallel analyses.ICRISAT Journal Article No. 1200