Organic and mineral fertilization management improvements to a double-annual cropping system under humid Mediterranean conditions

The efficient use by crops of nitrogen from manures is an agronomic and environmental issue, mainly in double-annual forage cropping systems linked to livestock production. A six-year trial was conducted for a biennial rotation of four forage crops: oat-sorghum (first year) and ryegrass-maize (second year) in a humid Mediterranean area. Ten fertilization treatments were introduced: a control (without N); two minerals equivalent to 250 kg N ha⁻¹ year⁻¹ applied at sowing or as sidedressing; dairy cattle manure at a rate of 170, 250 and 500 kg N ha⁻¹ year⁻¹ and four treatments where the two lowest manure rates were supplemented with 80 or 160 kg mineral N ha⁻¹ year⁻¹. They were distributed according to a randomized block design with three blocks. The highest N mineral soil content was found in the summer of the third rotation, in plots where no manure was applied. The yearly incorporation of manure reduced, in successive cropping seasons, the amount of additional mineral N needed as sidedressing to achieve the highest yields. Besides, in the last two years, there was no need for mineral N application for the manure rate of 250 kg N ha⁻¹ year⁻¹. This amount always covered the oat-sorghum N uptake. In the ryegrass-maize sequence uptakes were as high as 336 kg N ha⁻¹ year⁻¹. In the medium term, the intermediate manure rate (250 kg N ha⁻¹ year⁻¹) optimizes nutrient recycling within the farming system, and it should be considered in the analysis of thresholds for N of organic origin to be applied to systems with high N demand.     

农杆菌介导的燕麦创伤胚转化体系研究

通过建立遗传转化体系,培育具有特定功能的转基因作物品种对改善作物的生存能力和生态环境适应力具有重要意义。参照农杆菌划胚介导植物萌发种子基因转化方法,以农杆菌菌株LBA4404(含质粒p CAMBAR.CH I.11)侵染转化燕麦种子,对转化体系中的菌液浓度、超声波功率、种子处理方式和抗除草剂筛选等不同转化条件分别进行了研究,以探索农杆菌介导的燕麦最适宜的遗传转化体系。结果表明:燕麦种子浸泡4 h后采用穿刺法划伤种子,1 000 W超声波处理划伤种子10 min,在OD600=0.4的农杆菌溶液中共培养2 d,最有利于种子转化;用0.8 mg/L草丁膦溶液与种子共培养能够有效抑制种子萌发进行初筛,用1 mg/L草丁膦溶液喷施幼苗进行除草剂抗性筛选,能够明显抑制假阳性苗的生长;将来自链霉菌(Streptomyces hygroscopicus)的Bar基因导入燕麦,经除草剂筛选以及Bar基因的PCR检测和Southern杂交分析证明获得转基因植株。     

9个燕麦品种在齐齐哈尔地区的农艺性状及饲草品质评价

为筛选出适宜在齐齐哈尔地区推广种植的燕麦品种，用基于熵权的灰色关联方法对9个燕麦品种的农艺性状和饲草品质进行综合评价。结果发现，9个品种中，梦龙株高达到120 cm以上，与吉利和摩登差异不显著，但显著高于其他品种(P<0.05);悍马鲜草产量最高(49 395 kg·hm^-2),龙牧12号干草产量最高(13 837 kg·hm^-2)。9个燕麦品种的可溶性碳水化合物(WSC)、粗蛋白(CP)、粗脂肪(EE)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、粗灰分(ASH)、木质素(ADL)含量和相对牧草质量(RFQ)分别为10.52%～12.55%、6.58%～9.88%、1.96%～2.83%、32.67%～39.52%、59.47%～68.34%、6.99%～10.40%、3.50%～4.47%、85.00～110.67。梦龙、龙牧12号和吉利的CP含量显著低于其他品种(P<0.05);泰克的ASH含量显著高于其他品种(P<0.05);龙牧12号的ADF和NDF含量均显著高于其他品种(P<0.05)。应用灰色关联度法...     

Understanding the role of oat β-glucan in oat-based dough systems

B-glucan is one of the components that differentiate oats from other cereals and that contribute to the health-related value of oats. However, so far oats cannot easily be applied in bread-like products without loss of product quality. Here we have studied how the content and viscosity of oat β-glucan affect the technological properties of oat dough in both a gluten-free and a gluten-containing system. In both systems, increasing the β-glucan concentration resulted in an increase of dough stiffness and in a reduction of dough extensibility. β-glucan negatively impacted the elastic properties that additional wheat gluten conferred to oat dough. This effect was smaller for medium-viscosity β-glucan than for high-viscosity β-glucan. Interestingly, dough made from low β-glucan flour (<2%) had increased gas retention capacity. Overall, the impact of β-glucan on the properties of oat dough systems was governed by concentration and viscosity, with or without additional wheat gluten. Our findings indicate that β-glucan is a key component that determines the rheology of oat-based dough systems and, with that, the technological functionality of oat in dough systems.     

西北绿洲灌区水氮耦合对燕麦品种陇燕3号耗水特性及产量的影响

灌水和施肥,尤其是施氮肥,是调控作物生长和增加产量的两大重要技术措施,其互作是燕麦高产高效栽培中重要因素。2014—2015年连续2个生长季,在甘肃河西绿洲灌区的田间试验设3个定额灌溉和3个施氮(纯氮)水平,研究水氮耦合对陇燕3号农田0~150 cm土层耗水量、棵间蒸发、产量及水分利用效率的影响。3个灌溉处理的灌水量分别为270 mm(I_1)、337.5 mm(I_2)和405 mm(I_3),3个施氮水平分别为90 kg hm~(–2)(N_1)、120 kg hm~(–2)(N_2)和150 kg hm~(–2)(N_3)。从播种到成熟,燕麦阶段耗水强度呈先增后减趋势,抽穗至灌浆是最大耗水期,且同一施氮水平下,阶段耗水强度随灌水量增大而显著增加。在全生育期内,棵间蒸发量(E)及土壤水分蒸发量占总蒸发量的比例(E/ET)表现先降后升趋势,且相同施氮量下,拔节至灌浆期随灌水量的增大而增大,而灌浆至成熟期则随灌水量的增大而减小。相同施氮量下,燕麦产量随灌水量增加而显著增加,水分利用效率却随灌水量增加而降低。产量N_3I_3最高(5466.0~5727.5 kg hm~(–2)),N_3I_2次之(5428.5~5678.5 kg hm~(–2)),N_1I_1最低(4504.5~4804.3 kg hm~(–2));水分利用效率N_3I_2最大(12.11~12.82 kg mm~(–1) hm~(–2)),N_3I_1次之(12.04~12.63 kg mm~(–1) hm~(–2)),N_1I_3最小(9.79~10.58 kg mm~(–1) hm~(–2))。由此表明,水氮耦合对燕麦水分利用及产量具有显著互作效应。施氮量150 kg hm~(–2)、灌溉定额337.5 mm是西北绿洲灌区燕麦种植较佳的节水、高产水氮管理模式。     

良种燕麦在海北地区的引种栽培试验

在海北高寒地区对6种良种燕麦进行引种比较试验,结果表明,在海拔3100m地区,青海444和87—444两个品种种子完全能成熟,全生育天数为126d,其他品种由于气温低（年均温-0．1℃）,生长季短,种子不能完全成熟,但籽实产量和产草量均极显著高于当地黄燕麦。青引2号在海拔2800m以下种植,种子完全能成熟,籽实产量平均达3336．4kg／hm^2,生育期为120d左右,可在当地进行种子繁殖。     

红叶病在燕麦不同生育时期的发生情况及对种子产量的影响

为了明确红叶病在燕麦不同生育时期的发生情况及其对种子产量的影响,对甘肃中部地区的12份田间栽培燕麦材料在分蘖期、拔节期、抽穗期、灌浆期和乳熟期的红叶病发生情况进行调查,并测定了燕麦成熟期的种子产量、有效分蘖数、穗长、小穗数、不育小穗数、穗粒数、穗粒重和千粒重等指标。结果表明:红叶病的发病严重度与燕麦生育时期相关,各供试材料从抽穗期开始发病,随生育期的推移而不断加重,乳熟期发病最为严重,平均严重度在3.26~4.70之间。灌浆期的病害严重度与燕麦种子产量呈极显著负相关(P<0.01,r=-0.781),也与穗粒数、穗粒重、千粒重呈极显著负相关(P<0.01)。在所有供试材料中,Rigdon发病较轻,种子产量最高(3652.78kg/hm^2),综合表现最好;479次之;青永久237最差。     

牧草专用肥对环青海湖地区燕麦生产效果的试验

环青海湖地区是高效畜牧业生产示范区,本地区人工草地面积近1万公顷,而人工草地中燕麦生产占95%以上,燕麦生长发育过程中,营养状况的改善是不可忽视的一个重要方面。通过施用牧草专用肥后,与当地习惯施肥水平相比,燕麦产量提高38%,增收167.5～251.9元,经济效益显著。     

Avenanthramide concentrations and hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyltransferase activities in developing oats

Avenanthramides are unique components of oats (Avena sativa L.) that are described as phytoalexins and that have potential health promoting properties. The objectives of this study were to examine the avenanthramide contents and the activity of the avenanthramide biosynthetic enzyme hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyl transferase (HHT) in spikelets and leaves of developing field-grown oats and to examine the presence of avenanthramides in unelicited seedling leaves of oats raised in a growth chamber. Avenanthramides were evident in spikelets of field-grown plants within 3–5 days after heading, and they generally increased in concentration throughout maturation. HHT activity was not detected until 21–22 days after heading, but the activity increased with age in most cultivars. In leaves, avenanthramides were evident before heading and generally increased in concentration until about 15 days after heading. At maturity, the concentrations of avenanthramides in spikelets were generally higher than in leaves. Seedling leaves from controlled environments that were not exposed to elicitors had low concentrations of avenanthramides at 7 days after planting, which increased in one cultivar, but not in another, over the next 14 days. These results indicate that unelicited seedling leaves contain avenanthramides, i.e. that avenanthramides are constitutively present in both grains and leaves.     

高寒牧区牧草引种及混播技术的研究

在海拔高度近4000m的高寒牧区对10个燕麦优良品种进行引种比较试验，结果表明，10个品种均不能成熟，只能达到孕穗期，其中丹麦444、巴燕5号和选18等3个品种的青干草产量极显著高于对照巴燕3号，可在该地区推广种植。21个多年生禾草品种的引种试验表明，其产草量和越冬性能，上繁草中以垂穗披碱草，多叶老芒麦、紫野麦草较好；下繁草以中华羊茅、西北羊茅、毛稃羊茅、冷地早熟禾、紫羊茅（同德）、星星草为好。混播试验表明，多叶老芒麦30％＋中华羊茅70％的垂穗披碱草70％＋西北羊茅30％在第二、三年群落结构和产草量优于其它混播处理和单播。说明在高寒牧区利用多年生禾本科牧草混播是解决人工草地品种单一，优化群落结构，提高产草量的较好途径。