Effect of Weed Removal on Productivity of Chickpea (Cicer arietinum L.) and Lentil (Lens culinaris Med.) in a Mediterranean Environment

Three field experiments were conducted on chickpea ( Cicer arietinum L.) and four on lentil ( Lens culinaris Med.) at different winter-sown rainfed locations in Jordan from 1988/89 to 1990/91 to study the effect of the duration of weed-free and weed-infested conditions on yields and yield components of the crops. Chickpea seed yields were reduced on average by 81 % and straw yields by 63 % when fields remained weed infested until harvest compared with weed-free conditions throughout the growing season. The corresponding lentil seed and straw yield decreases were 63 % and 55 %. As the duration of weed-free period increased and the duration of weed-infested period decreased, yields increased. However, the critical period of weed interference was between 35 and 49 days after emergence in chickpea and between 49 and 56 days after emergence in lentil, when these crops were at an advanced stage of vegetative growth. There were significant negative correlations between the weed dry weight and the seed or straw yields. The reduction in seed yields in both crops because of weed interference occurred mainly through the reduced number of pods /plant, which in turn was partly the result of reduced number of secondary branches. In chickpea, some reduction also occurred through reduced 100-seed weight.     

Transferability of Chickpea Selection Indices from Normal to Drought-prone Growing Conditions in a Mediterranean Environment*

Chickpea (Cicer arietinum L.) is normally grown as a spring-sown rainfed crop in the Mediterranean region in areas receiving more than 400 mm of rainfall annually. Because of large fluctuations in the total amount and distribution of the rainfall, the crop occasionally suffers from extreme terminal drought. Breeders face a dilemma in selecting materials for both normal moisture regimes and drought conditions because it is often difficult to conduct two parallel breeding programmes. This study examines the transferability of the selection indices (developed as a multiple regression of yield on most influential traits) from one environment to another with the objective of selecting an appropriate environment for the development of cultivars adapted to both environments. Experiments were conducted for 3 years (1989-1991) during the spring at two locations with normal moisture regime (hereafter referred to as drought-free) in Syria and Lebanon and one drought-prone location in Syria. Each year, 192-240 newly bred lines were evaluated in replicated trials for seed yield, days to flowering and maturity, plant height and 100-seed weight. Correlation analyses showed that increased seed size, early maturity and reduced plant height at the drought-prone location and early maturity at the drought-free location were of prime importance in increasing seed yield. Regression equations developed to predict seed yield showed that days to flower and maturity accounted from 67-80 % variation in seed yield at the dry location, whereas at the drought-free locations the contribution of days to maturity was smaller except in 1991 in Lebanon. The percent success in the transferability of the selection indices from the drought-free environments to the drought-prone environment was higher than that from the drought-prone environment to the drought-free environment. These results indicate that chickpea breeding material developed under drought-free environments could be useful under drought-prone conditions. Early-maturing lines selected under normal environments would also perform well under drier conditions.     

Dinitrogen Fixation by Winter Chickpea Across Scales in Waterlogged Soil in a Mediterranean Climate

Studies on N₂ fixation by grain legumes during periods of winter waterlogging prone Mediterranean regions have rarely been performed across scales. Here, we quantified the spatial variability of N₂ fixation by rain‐fed chickpea (Cicer arietinum L.) at the field‐ and micro‐scales (0.15 m spacing) after waterlogging during the vegetative growth phase in the winter. We also determined effects of tillage (standard and minimum) and crop and soil variables on N₂ fixation in water stressed conditions. After waterlogging, yield was greatly reduced but there were no visible signs of water stress or tillage effects on N₂ fixation. At the field scale, percent N derived from N₂ fixation (%Ndfa) ranged from 51 to 93 % and was related to the amount of soil‐derived N in the plant. Total grain N did not increase when N₂ fixation increased and the amount of N derived from the soil was replaced with fixed N. In contrast, %Ndfa at the micro‐scale, ranging between 0 to 72 %, was primarily related to yield and total plant N whereas available soil N or any of the other measured soil properties were not significant predictors of %Ndfa. Total N in the grain increased solely due to N₂ fixation as the contribution from soil N remained constant. Although %Ndfa had a nearly pure nugget variance across the scales, total N derived from N₂ fixation (gNdfa) showed a relatively high level of spatial correlation. The range of available soil N pools was likely different at the two scales, leading to differences in the responses of chickpea N₂ fixation to available soil N.     

Irrigation Decreases Loss of Leaf Nitrogen and Rubisco During Pod Development in Chickpea

Chickpea ( Cicer arietinum L., var. Pusa 256) plants raised under unirrigated and irrigated field conditions showed a decrease in leaf nitrogen and soluble protein content after flowering during pod development. This was found to be associated with a decrease in Rubisco content after flowering. Leaf nitrogen, soluble protein and Rubisco content, however, were higher in irrigated than in unirrigated plants. The Rubisco content at the flowering and post-flowering stages was 29.43 and 16.59 %, respectively, of leaf soluble protein in unirrigated plants. Under irrigated conditions, the Rubisco content was 49.91 and 37.99 %, respectively, at the flowering and post-flowering stages. These results therefore indicated a decrease in the mobilization of leaf nitrogen by irrigation in chickpea. The findings are discussed in relation to the decrease in seed yield and harvest index by irrigation commonly observed in this crop under north Indian conditions.     

Using the CERES-Maize model in a semi-arid Mediterranean environment. Evaluation of model performance

The CERES-Maize model was tested in a semi-arid Mediterranean environment during a period of 2 years under three different soil moisture conditions (well-watered and two limited irrigation regimes). In well-watered plots, growth and yield were adequately simulated by the model (differences between simulated values and observations were less than 10%). Results suggest that the absence of air humidity among the model inputs does not limit the CERES-Maize performance, even under dry-air conditions. On the contrary, under mild soil water shortage, CERES-Maize underestimated the leaf area index (LAI) (up to 26% for maximum LAI), above-ground biomass (up to 23%) and grain yield (up to 15%). Mismatches between observations and predictions increased with water stress level (by up to 46, 29 and 23% for maximum LAI, biomass and grain yield, respectively). It is suggested that the functions describing leaf growth and senescence and those calculating the soil water deficit functions should be modified to adapt CERES-Maize to Mediterranean environments.     

鹰嘴豆miRNA中miR156家族的生物信息学分析及靶基因预测

为了揭示鹰嘴豆Car-miR156基因家族的进化过程和表达模式,对Car-miR156家族8个成员的序列进行生物信息学分析及靶基因预测。染色体定位结果表明7个Car-miR156基因定位在鹰嘴豆Ca4、Ca5、Ca6和Ca7四条染色体上,而Car-miR156g定位在scaffold1580上。序列比对发现8个Car-miR156基因的成熟序列具有高度一致性,仅在5'端第1、14和15个碱基存在差异。二级结构分析结果表明,8个Car-miR156成员的前体序列都能形成稳定的茎环结构,Car-miR156h成熟的miRNA序列位于3'端,Car-miR156a/b/c/d/e/f/g成熟的miRNA序列位于5'端。此外,Car-miR156a/d/f/g与大豆的miR156家族成员亲缘关系较近,Car-miR156e与拟南芥Ath-miR156j聚在一个分支,而Car-miR156b单独为一个分支。靶基因预测表明SQUAMOSA启动子结合蛋白家族成员(SPL2/3/6/7/9/13A)是Car-miR156的靶基因,Car-miR156a/c/d/e/f/g/h还能够靶向调控大刍草颖片架构1类基因。转录组数据分析表明,Car-miR156a/c/d/f在鹰嘴豆8个组织中都有表达,Car-miR156b在根中不表达,Car-miR156e在茎和花中不表达。这些研究结果为研究鹰嘴豆Car-miR156家族成员的表达及其靶基因的功能提供了基础。     

Studies on Sowing Depth for Chickpea (Cicer arietinum L.), Faba Bean(Vicia faba L.) and Lentil (Lens culinaris Medik) in a Mediterranean-type Environment of South-western Australia

Pulses such as chickpea, faba bean and lentil have hypogeal emergence and their cotyledons remain where the seed is sown, while only the shoot emerges from the soil surface. The effect of three sowing depths (2.5, 5 and 10 cm) on the growth and yield of these pulses was studied at three locations across three seasons in the cropping regions of south-western Australia, with a Mediterranean-type environment. There was no effect of sowing depth on crop phenology, nodulation or dry matter production for any species. Mean seed yields across sites ranged from 810 to 2073 kg ha⁻¹ for chickpea, 817–3381 kg ha⁻¹ for faba bean, and 1173–2024 kg ha⁻¹ for lentil. In general, deep sowing did not reduce seed yields, and in some instances, seed yield was greater at the deeper sowings for chickpea and faba bean. We conclude that the optimum sowing depth for chickpea and faba bean is 5–8 cm, and for lentil 4–6 cm. Sowing at depth may also improve crop establishment where moisture from summer and autumn rainfall is stored in the subsoil below 5 cm, by reducing damage from herbicides applied immediately before or after sowing, and by improving the survival of Rhizobium inoculated on the seed due to more favourable soil conditions at depth.     

Effect of Time of Harvest of Vetch (Vicia sativa L.) on Yields of Subsequent Barley in a Dry Mediterranean Environment

The introduction of annual feed legumes into the intensifying systems of barley monocropping in dry-area Mediterranean agriculture would reduce pest and disease risk and increase sustainable productivity. Potential modes of legume utilization by small ruminants — as green grazing, hay, or mature grain and straw — imply different times of harvest removal with possible consequences for the subsequent barley crop. In nine two-year trials, barley following green-grazed common vetch (Vicia sativa) always outyielded barley following vetch cut as hay or harvested at maturity, albeit in some years by small and non-significant margins; mean differences in barley grain and straw yields between green-graze and mature vetch treatments were around 20 %. The main mechanisms implicated are carryover to the barley of small amounts of soil water unused by early-harvested vetch and enhanced nitrogen availability where active vetch root systems were killed by removal of the above-ground crop.     

绿洲膜下滴灌调亏对马铃薯土壤环境及产量的影响

为测定膜下滴灌调亏马铃薯全生育期内不同调亏水平土壤养分、土壤水热动态、生长动态、产量效应和水分利用效率,于2016年在河西荒漠绿洲灌区民乐县益民灌溉试验站开展了马铃薯不同生育阶段水分调亏灌溉的试验研究,结果表明,马铃薯膜下滴灌调亏土壤水热变化均匀且利用率高,有利于马铃薯对土壤养分的充分吸收和利用;土壤养分是土壤肥力的核心,是植物在生长发育过程中不可或缺的重要因素,膜下滴灌调亏栽培能有效减少土壤速效养分的流失,并提高马铃薯对土壤速效养分的利用效率;不同生育阶段马铃薯耗水量受水分调亏程度影响较大,其耗水量随调亏程度增大而显著减少(P0.05),水分调亏处理马铃薯全生育期总耗水量均低于全生育期充分灌水CK处理。块茎形成期轻度水分亏缺马铃薯水分利用效率、灌溉水利用效率、生物量均达到最大,较全生育期充分灌水显著提高29.04%,35.61%。因此,块茎形成期轻度水分亏缺灌溉方式能使马铃薯根区土壤始终保持湿润状态,有效减少渗漏损失和植株间无效蒸发损失,改善土壤水、肥和热量状况,有利于提高作物水分利用效率,且不显著降低马铃薯最终产量。     

根系不同分隔方式下油菜和鹰嘴豆对小麦锰营养的影响

通过根系分隔盆栽试验,研究了油菜和鹰嘴豆对小麦生长及锰营养的影响.结果表明:与油菜或鹰嘴豆混作能显著改善小麦生长及锰营养,其地上部干质量和吸收锰量均以根系不分隔处理显著高于根系完全分隔处理,但油菜和鹰嘴豆的生长受小麦抑制,表现为不分隔处理地上部干质量及吸锰量显著低于完全分隔.不施锰小麦/油菜和小麦/鹰嘴豆混作体系中,根系不分隔处理小麦根区土壤DTPA-Mn含量显著高于其他分隔方式,且油菜或鹰嘴豆地上部植株锰含量显著高于相应的混作小麦,在锰胁迫条件下,油菜和鹰嘴豆根系活化的土壤锰可被小麦吸收利用.因此与油菜或鹰嘴豆混作是改善小麦锰营养的有效途径之一.     

Factors affecting the genotype × environment interaction in spring triticale grown in a Mediterranean environment

The identification of the genotypic and environmental factors responsible for the genotype by environment interaction is essential in any breeding program. A Multi Environmental Trial (MET) including 3 years, 3 locations and 14 lines of spring triticale (× TriticosecaleWittmack) was carried out in a Mediterranean environment (Sardinia, Italy). Water available to the crops was calculated through a model run with the environmental variables and the phenological data recorded in each environment. Yield, yield components and heading date were used to perform an Additive Main effects and Multiplicative Interaction (AMMI) analysis. Interaction for yield was relevant only in 2 environments out of 8, one characterised by a late sowing, the other by the warmest pre-anthesis period. Correlations between Interaction Principal Component Axis (IPCA) scores and environmental and genotypic variables showed that genotype by environment interaction for yield and kernels per m² is related to interaction for phenology but not to the yield level. Yield level was significantly correlated with the water availability. Genotype by environment interaction for yield is mainly determined by thermal conditions in the pre-anthesis period, genotypic photoperiodic sensitivity and sowing time. This revised version was published online in August 2006 with corrections to the Cover Date.     

畦灌糙率系数的变异规律及其对灌水质量的影响?

摘要：【目的】糙率系数是地面灌溉设计和管理的基本参数之一。为了更好地进行地面灌溉系统的设计和管理,研究了畦灌糙率系数的变异规律,并分析了其对灌水效果的影响。【方法】在110m的畦田长度上,观测了水流推进过程及沿程各点的水深,采用曼宁公式的数值解法估算了26条畦田的田面糙率系数,分析了其变异规律,评价了糙率系数对灌水质量评价指标的影响。【结果】结果表明,裸地畦田的平均糙率系数在0.038左右,其变异程度为中等强度。对试验区域内各畦田灌水模拟结果显示,当采用平均糙率系数模拟灌水效果评价指标时,与采用各畦田实际糙率系数相比,灌水效率指标最大相对误差达6.48%,灌水均匀度最大相差66.67%。【结论】因此,在实际地面灌溉设计与管理中,糙率系数的这种差异性不可忽略。     

春季不同灌水处理对冬小麦产量的影响

在河北省5个试验基点研究了大田实验条件下冬小麦春季不同灌水处理的产量效应。结果表明,随灌水次数的增加,小麦产量增加。春灌两水和春灌三水处理籽粒产量显著高于一水处理的产量,但两水与三水处理产量之间没有显著差异。灌溉水的利用效率随灌水次数的增加而降低。初步认为,在选择适宜品种的基础上,河北省大部分麦区冬小麦春季生产上合理的节水灌溉方案为:拔节水、开花水。与传统灌溉技术相比,在冬小麦获得相近产量的前提下,春季灌水次数减少2次,小麦生育期间节水80￣100m3,提高了灌溉水的利用效率。     

Chickpea and faba bean nitrogen fixation in a Mediterranean rainfed Vertisol: Effect of the tillage system

Efficient management of legumes in order to maximize benefits depends on a correct field assessment of N₂ fixation. A field experiment was conducted during a 6-year period (2001–2002 to 2006–2007) in Córdoba (Southern Spain) on a rainfed Vertisol within the wheat-chickpea and wheat-faba bean rotation framework of a long-term experiment started in 1986. The aim was to determine the effect of tillage systems [no tillage (NT) and conventional tillage (CT)] on chickpea and faba bean N₂ fixation. Fixation was calculated using the ¹⁵N isotopic dilution (ID) and ¹⁵N natural abundance (NA) methods with the reference being the wheat crop. The strong inter-annual rain variation caused great differences in the behaviour of both leguminous plants with regard to grain yield, nodule biomass and N₂ fixation. The NT system showed more nodule biomass than the CT system in both legumes. The ID method was more accurate than the NA method in determining N₂ fixation. The average amount of fixed N in faba bean (80 kg ha^?1 year^?1) was much greater than that in chickpea (31 kg ha^?1 year^?1). The Vertisol under the NT system offered more favourable conditions for the stimulation of the N₂ fixation, with fixed N values that were significantly higher than under CT. The N added to the system through N₂ fixation was low in faba bean and virtually nonexistent in chickpea, only in terms of above-ground biomass.     

Estimation of Outcrossing Rate in Chickpea (Cicer Arietinum L.) Sown in Autumn

Gene flow via outcrossing from transgenic plants to relatives will be one of the most important concerns to grow of the transgenic chickpea (Cicer arietinum L.) in European Union (EU). This report is therefore focused on spontaneous outcrossing rate in chickpea. A total of 39 kabuli type mutants with white flower and one desi type with pink flower were grown to estimate spontaneous outcrossing rate. Outcrossing rate ranged from 0.0 to 1.25% in mutant materials. Since labelling threshold for transgenic contamination in food and feed in European Union (EU) is 0.9%, outcrossing rate of 1.25% is higher than threshold of 0.9% in EU, and this result suggests that cultivation of transgenic chickpea will be under high risk to be contaminated chickpeas in neighbourhood fields.     

Barley—Salt-Bush Intercropping for Sustainable Feed Production in a Dry Mediterranean Steppe Environment

Dry rangelands in the Syrian steppe have been degraded by overgrazing and incursions of barley cultivation. Replanting with Atriplex spp. (salt-bush) is recommended for rehabilitation; but, for land already ploughed, growing barley between atriplex hedges may be the best compromise, providing complementary feed sources and soil protection against wind erosion. The trial described here measured the biomass output of barley and atriplex browse material in a range of treatments, in which hedge dimensions and crop-strip widths were varied in partial factorial combination. Results over 6 years showed little interaction between hedges and barley crop, but growing the two together tended to buffer total feed output against annual fluctuations due to rainfall variability. An apparent decline in atriplex vigour towards the end of the study period drew attention to the need to optimize browsing pressure on the shrubs. Altogether, the indications are that barley-atriplex systems have potential to provide sustainable production in currently degraded steppe areas, but essential conditions for success will be full control of land access and skilled management of atriplex shrubs.     

畦灌改水成数的控制误差及其对灌水质量的影响

改水成数是地面灌溉设计和管理的基本参数之一。为了更好地进行地面灌溉系统的设计和管理,统计了畦灌改水成数的控制误差,并分析了其对灌水质量的影响。根据实测的16条畦田不同改水成数的控制误差,采用经典统计学方法得到了其统计特征,并采用地面灌溉模拟模型SRFR评价了其对灌水质量的影响。结果表明,改水成数控制误差具有较强的变异性,改水成数对灌水均匀度的影响大于灌水效率。因此,在实际地面灌溉设计与管理中,改水成数的控制误差不可忽略。较大的单宽流量有助于减小改水成数的控制误差对灌水质量的影响。     

膜下滴灌对棉田生态环境及作物生长的影响

通过田间试验研究了膜下滴灌对棉田生态环境状况及棉花生长发育及产量形成的影响。结果表明,膜下滴灌与常规灌溉相比,覆膜滴灌改变了棉花田间水分环境,为棉花的生长创造了良好的水、肥、气、热条件,有利于棉花生长发育;同时,可以减少地面蒸发,减少灌溉水的深层渗漏, 保持土壤肥力, 提高水分利用率, 增加作物产量,具有良好的经济、生态和社会效益。     

灌溉方式和播期对玉米水分动态与水分利用效率的影响

为明确不同灌溉方式、不同播期下产量与水分利用效率和耗水量的关系,通过设置滴灌、喷灌、漫灌3种灌水处理和3期分期播种的对比试验,在浇底水前、播种、收获和每旬未每区用土钻法取1 m深土样,用烘干称重法测定土壤含水率,用对比分析的方法研究同一品种在滴灌、喷灌、漫溉条件下和不同播期玉米需水耗水规律。结果表明,滴灌的土壤水分分布及变化对玉米生长最有利,喷灌次之,漫灌最差。滴灌实产最高,耗水量最小,水分利用效率最高,产量次高耗水最少的第三期玉米用水效率最高。滴灌在保证玉米需水的前提下储水能力最强,是干旱缺水地区的高效灌水方式。晚播、晚熟玉米品种有更好、更大的生产潜力和可推广性,就水热匹配来看晚播、晚熟玉米品种也是提高水分利用效率的一种途径。滴灌平均实产较喷灌增加1.69%,较漫灌增加6.53%,耗水量较喷灌减少2.9%,较漫灌减少16.1%,水分利用效率较喷灌增大4.7%,较漫灌增大26.9%,第三期平均实产较第一期增加2.76%,较第二期减少2.81%,耗水量较第一期减少18.2%,较第二期减少18.3%,水分利用效率较第一期增大25.6%,较第二期增大19%。     

灌溉处理对苜蓿木质素单体分布影响的研究

为给苜蓿品质改良提供科学依据,选用‘新牧1 号’杂花苜蓿为试验材料,采用组织化学染色方法研究灌溉量对苜蓿茎木质素单体分布的影响。结果表明随灌溉量增加,株高和节数呈递增趋势;灌溉量对苜蓿茎木质素单体厚度和比例具有显著影响,750 m3/hm2灌溉量较其他灌溉处理有较多的木质素单体分布;2种木质素单体分布范围存在显著差异,S木质素单体厚度和比例均高于G木质素单体。