砂引发对荞麦种子萌发及活力的影响

试验选用安徽甜荞-1、安徽甜荞-2、青海甜荞、青海苦荞4个荞麦种子样品为材料,每品种设置4种处理,研究不同含水量的砂基质引发对荞麦种子萌发及活力的影响。结果表明,适宜的砂引发处理能不同程度地提高荞麦种子的活力,砂引发基质的适宜含水量安徽甜荞-1、安徽甜荞-2和青海甜荞均为5．7％,青海苦荞为3．8％。     

水稻种子在不同气候区室温贮藏的适宜含水量及存活特性

 将不同含水量水平的两个水稻品种幸实(粳稻)和桂朝2号(籼稻)分别贮藏在三亚、南昌、北京、西宁、乌鲁木齐和哈尔滨等6个不同气候类型地区。通过11年的逐年生活力测定,研究了水稻种子室温贮藏的适宜含水量及其存活特性。结果表明,水稻种子经适当干燥后其生活力和活力没有显著下降。但当种子含水量在30％以下时种子的生活力和活力受到影响。获得了水稻种子在三亚、南昌室温贮藏时（贮藏温度不是恒定的）的适宜含水量,且适宜含水量50％~65％具有地域的广适性。相对于其他含水量,适宜含水量种子在贮藏过程中,其生活力快速下降阶段推迟,且适宜含水量上限和极差与贮藏地点年均温和≥0℃积温呈显著或极显著负相关,且适宜含水量下限与之呈显著或极显著正相关。种子在年均温度相同的西宁和乌鲁木齐的贮藏效果不同,≥0℃积温和气候温差波动的差值可能是其主要影响因素。     

间作条件下水肥运筹对花生和谷子产量的影响

[目的]探讨花生和谷子间作条件下水肥运筹对作物产量的影响。[方法]采用水、氮、磷"3414"试验设计,研究间作条件下不同水肥处理对花生和谷子产量的作用效果。[结果]间作条件下花生和谷子产量对水肥的响应较为一致,土壤水分养分与花生产量相关性由强至弱依次为土壤水分氮施用量磷施用量,与谷子产量相关性由强至弱依次为土壤水分磷施用量氮施用量。水、氮、磷三因素合理配施能够降低水肥投入量,提高水肥利用效率。花生谷子间作条件下,适宜土壤含水量均较低,可在大部分半干旱地区雨养种植。各因素之间,磷肥与水的耦合作用肥料之间的耦合作用氮肥与水的耦合作用。间作条件下,花生适宜的土壤含水量为占田间持水量的57.3%,适宜的氮素和磷素施用量分别为0.49 g/盆和0.2 g/盆,谷子适宜的土壤含水量为占田间持水量的59.1%,适宜的氮素和磷素施用量分别为0.29 g/盆和0.23 g/盆。[结论]研究结果为该种种植模式的应用和推广提供理论和技术参考。     

引发剂结合固体基质引发对三倍体西瓜种子发芽性能的影响

种子发芽出苗率低是制约三倍体无籽西瓜生产的主要原因。试验以红小玉为材料,用0.1%H2O2,0.1%CuSO4+2%KNO3+KH2PO4混合液和20 m g/kg的GA3丙酮溶液作引发剂,在固体基质中吸湿32 h后回干,通过砂床发芽试验,测定种子萌发率和幼苗素质。结果表明,种子萌发率提高了44.6~62.4个百分点,并显著提高了发芽势、幼苗鲜重和根系活力。其中,GA引发处理的种子发芽率达88.23%,与破壳处理(CK 1)接近,比未处理(CK 2)提高了62.47个百分点;3种处理的苗鲜重均显著高于CK 1和CK 2,处理间差异不显著;3种处理均显著提高了幼苗根系活力,以0.1%H2O2处理效果最佳。3种引发剂结合固体基质引发处理,均可有效提高三倍体西瓜种子萌发率,并为培育壮苗奠定了基础。在固体基质处理过程中,西瓜种子吸水缓慢,给细胞膜的修复提供了时间,是种子可以达到引发促萌的原因之一。     

径山茶适制品种的研究与推广

用浙农139、浙农117、龙井长叶、乌牛早、薮北种、茂绿(品系)品种加工成"径山茶",以鸠坑种为对照,通过制茶品质审评、发芽期观测和理化检测,浙农139、浙农117、龙井长叶、茂绿4个品种品质均符合"径山茶"标准,春茶开采比鸠坑种早、经济效益高,达到较大的经济和社会效益,适宜在径山茶产区推广。     

水分胁迫条件下氮素营养对不同冬小麦基因型的生理效应

为给旱地小麦高产栽培和氮素高效利用提供依据,以水氮高效型品种小偃22和水氮低效型品种小偃6号为供试材料,通过水培试验,研究了水分胁迫下介质氮素营养对冬小麦幼苗根系和冠层干重、叶片相对含水量、根系活力、叶片叶绿素含量(SPAD值)等生理指标的影响.结果表明,水分胁迫和介质氮素供应对小麦幼苗各生理指标均有显著影响.水分胁迫下,介质供氮显著提高冠层干重、叶片相对含水量、根系活力及叶片叶绿素含量,降低根干重.而在供氮条件下.水分胁迫导致小偃22根系和冠层干重均明显降低,而小偃6号根系和冠层干重均明显增加,两个品种的叶片相对含水量(P<0.05)和根系活力(P>0.05)显著降低,培养阶段前期的叶片叶绿素含量提高.在介质缺氮条件下,水分胁迫使小偃22和小偃6号冠层干重分别增加和下降,两个品种根干重和叶片叶绿素含量均明显下降,叶片相对含水量和根系活力均增加.说明改善介质氮素营养可增强水分胁迫下小麦抗旱能力,促进冠层干物质积累,同时也增大小偃22根、苗干物质积累和两个品种叶片相对含水量对水分胁迫的敏感性,而降低了小偃6号根系和冠层干物质积累及两个品种根系活力和叶绿素含量对水分胁迫的敏感性.     

辽北地区几个谷子品种生产能力的比较

通过对辽北地区现有8个谷子品种进行对比试验，对各品种生育性状及产量构成因子的分析，筛选出适宜辽北地区种植的优质高产谷子品种铁谷11号、铁谷8号、铁谷10号，为种植业结构调整提供科学依据。     

高产小麦灌浆籽粒含水量及茎节伤流强度的昼夜变化

为给小麦高产栽培提供依据,以两个半冬性高产小麦品种周麦22和豫农202为材料,研究了灌浆盛期小麦籽粒含水量、基部茎节和穗茎节伤流强度昼夜变化动态及其相关关系.结果表明,小麦籽粒有效含水量白昼低,夜间高,呈“U”型变化趋势,强势粒有效含水量高于弱势粒;两个小麦品种茎节伤流强度的昼夜变化趋势大体相同,表现为白昼高、夜间低;基部茎节与穗茎节伤流强度差异显著,前者约是后者的1.83～4.84倍,且存在品种间差异.高产小麦灌浆盛期籽粒含水量、茎节伤流强度均表现出昼夜变化趋势和较高活力.     

农杆菌介导大豆子叶节遗传转化体系的优化

利用农杆菌菌株EHA105,对17个栽培大豆品种的大豆子叶节进行了侵染,从大豆基因型、氯气灭菌时间、外植体状态、菌株活力、侵染浓度、侵染时间、共培养时间等方面进行了优化。结果表明:氯气灭菌14~18 h,可在不影响大豆种子活力的同时最大限度的减少污染;暗处理1 d的外植体活力高于光照处理5~7 d的外植体;菌液浓度(OD600nm)在0.8~1.0且侵染浓度(OD600nm)为0.6~0.8时GUS瞬时表达率最高;适宜的侵染时间和共培养天数分别为30 min和4 d。在上述优化研究基础上,形成一套综合的转基因体系,该体系的最高转化率可达3.33%。不同处理下的GUS瞬时表达率以及17个大豆品种的丛生芽诱导率综合评价显示,适宜转化的基因型为TL-1、HC-3、HC-6、Williams 82。     

根瘤菌肥接种大豆的试验初报

以工程菌、出发菌、基质材料和空白对照四个处理，在大豆“黑农33”品种上进行接种试验。结果表明：工程菌效果最好，比对照增产18．4％，出发菌次之，比对照增产11．6％。     

人工草地青贮玉米高效灌溉制度研究

以内蒙古浑善达克沙地人工草地种植青贮玉米为研究对象,对两年灌溉试验数据应用FAO-56双作物系数法模拟计算了不同试验处理的青贮玉米实际需水量(蒸散量)。研究了需水量与玉米鲜物质产量、水分利用效率和边际产量之间的关系,并以水分利用效率和边际产量最高为原则确定了干旱地区青贮玉米高效用水灌溉制度。     

硝酸盐对大豆共生固氮的影响

大豆施用硝酸盐的试验结果表明,高浓度硝酸盐对吉林20号和长农4号的共生固氮有明显的抑制作用。低浓度硝酸盐在生育前期对吉林20号根瘤固氮酶活性有促进作用,酰脲含量增加,在生育后期有抑制作用。但生育前期低浓度硝酸盐对长农4号根瘤固氮酶活性有明显的抑制作用,酚脲含量减少。施用硝酸盐对大豆根瘤尿囊素酶活性都有抑制作用,生育前期比后期明显,高浓度比低浓度明显。     

低温胁迫后水分对水稻幼苗根系活力和水孔蛋白相关基因表达的影响

【目的】为了探究低温冷害胁迫后水分/湿度对水稻幼苗根系活力和水分运输等的影响,【方法】以具有低温耐性差异的嘉籼7号和辐8329两个水稻品种为研究材料进行低温胁迫处理后,在进行实验Ⅰ（不同湿度梯度,正常温度培养条件下）和实验Ⅱ（快速回温处理实验,以正常温度恢复为对照）。【结果】实验Ⅰ结果表明,与较低湿度（30%）相比,较高的湿度（60%和90%）可以提高根系活力,有效保证水稻幼苗的存活率并缓解其遭受的低温冷害。水孔蛋白基因OsPIP2;5和OsPIP2;6的表达水平与根系活力密切相关,对水稻的抗寒和低温耐性具有显著的调控作用。实验Ⅱ结果表明,与对照组（CK）相比,快速回温处理后水稻幼苗的含水量和根系活力显著降低;且正常自然恢复状态下,两个水稻品种的存活率明显高于快速回温组幼苗。【结论】低温胁迫显著影响水稻幼苗的生长发育过程。较高的湿度环境有助于缓解幼苗的低温冷害损伤,保证存活率。同时,低温胁迫后的外界环境湿度对水稻幼苗的含水量、根系活力和水孔蛋白相关基因表达有显著影响,其中OsPIP2;5和OsPIP2;6的表达水平与根系活力正相关,在水稻幼苗抵御外界低温冷害过程中起重要作用。因此,与低温胁迫后田间大量灌溉相比,正常温度下土壤缓慢的温度上升对幼苗的根系活力影响较小,有助于其在低温冷害后恢复生命活动。     

Deep Root Water Uptake Ability and Water Use Efficiency of Pearl Millet in Comparison to Other Millet Species

Abstract

Pearl millet is better adapted to hot and semi-arid conditions than most other major cereals. The objective of this study was to compare the deep water uptake ability and water use efficiency (WUE) of pearl millet among millet species. First, the WUE of six millet species was evaluated in pots under waterlogging, well-watered (control), and drought conditions. Secondly, the water uptake from deep soil layers by pearl millet and barnyard millet, which showed the highest drought and waterlogging tolerance, respectively, was compared in long tubes which consisted of three parts (two loose soil layers separated by a hardpan and a Vaseline layer). Soil moisture was adjusted to well-watered and drought conditions in the upper (topsoil) layer, while the lower (deep) layer was always kept wet. WUE was significantly reduced in all millet species by waterlogging but not by drought. The ratio of WUE to the control condition indicated that pearl millet had the highest and lowest resistances to drought and waterlogging conditions, respectively, while barnyard millet was the most stable under both conditions. The deuterium concentration in xylem sap water, relative water uptake from deep soil layers, and water uptake efficiency of deep roots were significantly increased in barnyard millet but not in pearl millet by drought in topsoil layers. In conclusion, the drought resistance of pearl millet is explained by higher WUE but not by increased water uptake efficiency in deep soil layers as compared to barnyard millet, another drought-resistant millet species.     

Elicitation of resistance and defense related enzymes by raw cow milk and amino acids in pearl millet against downy mildew disease caused by Sclerospora graminicola

Modulation of physiological and biochemical defensive responses against downy mildew (DM) of pearl millet induced by raw cow milk (RCM) and five amino acids is reported in this paper. In vitro conditions, none of the inducer treatments showed inhibitory action on DM pathogen. Significant enhancement of seed germination and seedling vigor was observed in RCM and amino acids treated seeds. Under greenhouse conditions, significant protection against DM was provided by l-phenylalanine (68.6%), l-isoleucine (66.5%) and l-proline (55.7%) treatments. Among the RCM treatments, the 10% dilution proved to be the best by offering disease protection of 35%. Spatio-temporal time gap studies indicated that seed treatment with l-phenylalanine increased disease resistance four days after inoculation. Seed treatments with RCM and amino acids also enhanced the vegetative and reproductive growth parameters of pearl millet when compared to the control. A similar trend in protection against DM was evident in the field trials. At the biochemical level, defense related enzymes such as phenylalanine ammonia lyase (PAL), peroxidase (POX) and β-1,3-glucanase showed an increased activity in RCM and amino acids treated seedlings than in sterile distilled water control seedlings. The highest PAL activity was recorded in RCM (10 and 20%) whereas in case of amino acids, the highest activity was observed in l-proline and l-phenylalanine treatments. The highest activity of β-1,3-glucanase was recorded in RCM (20%) and l-phenylalanine.     

Mixed Planting with Legumes Modified the Water Source and Water Use of Pearl Millet

Abstract

In semi-arid areas, pearl millet is an important staple food crop that is traditionally intercropped with cowpea. This study evaluated the water competition between pearl millet and cowpea using deuterated water. At vegetative stage, pearl millet biomass production was lower in the pearl millet-cowpea (PM-CP) combination than in the pearl millet-pigeon pea (PM-PP) and pearl millet-bambara nut (PM-BN) combinations. PM-CP used more water than PM-PP and PM-BN under well-watered conditions; however, all combinations used similar amounts of water under dry conditions. The biomass production, photosynthetic rates, transpiration rates, and midday leaf water potential of pearl millet at early flowering stage were not significantly reduced by mixed planting with cowpea sown two weeks later as compared with single planted pearl millet. When pearl millet and cowpea were sown at the same time, mix planting significantly increased the recovery rates of recently irrigated heavy water in pearl millet, but not in cowpea in both vegetative and early flowering stages. Midday leaf water potential and transpiration rates in pearl millet were lowered by mixed planting but those in cowpea were not. These indicate that the water source of pearl millet is shifted to the recently irrigated and easily accessible water. By contrast, when cowpea was sown two weeks later than pearl millet, this trend was not observed. These results provide new evidence on water competition in the PM-CP intercropping system; cowpea has higher ability to acquire existing soil water than pearl millet when both crops are sown at the same time.     

盐胁迫下亚精胺浸种对水稻种子萌发的影响

采用四个处理:A为清水对照,B为200 mmol/L NaCl,C为200 mmol/LNaCl+1.0 mmol/L Spd,D为1.0mmol/L Spd。对水稻种子进行处理,研究盐胁迫下亚精胺浸种对水稻种子萌发的影响。结果显示:用200 mmol/L NaCl溶液浸种时,种子萌发率明显降低,用1 mmol/L Spd溶液处理过的水稻种子,其发芽势、发芽指数、活力指数明显增加,并且胚芽的伸长长度增加。而用200 mmol/L NaCl溶液和1.0 mmol/L Spd溶液共同处理过的水稻种子,其发芽势、发芽指数、活力指数与对照无明显差别,说明亚精胺浸种不仅可以促进水稻种子的萌发,还可以缓解盐胁迫对水稻种子的毒害作用。     

PEG胁迫下甘蓝型油菜品种（系）种子发芽耐旱性鉴定

以10%（w/v）PEG6000做渗透介质模拟干旱条件,对不同来源的甘蓝型油菜(Brassica napus L.)品种（系）进行干旱胁迫下种子发芽鉴定,分析油菜种子发芽耐旱性的遗传多样性。结果表明：干旱胁迫下,部分材料处理与对照的发芽性状有显著性差异,81个甘蓝型油菜材料的平均苗高处理比对照低36.5％,平均鲜重处理比对照低31％,成苗率降低11.1％。甘蓝型油菜品种（系）耐旱性有较大遗传差异,幼苗活力指数的变异幅度为19％－81%,平均活力指数为55％。相关分析表明,活力指数与胁迫下的发芽性状达极显著正相关,可以作为油菜种子发芽耐旱的综合指标。根据活力指数,将81个油菜资源划分为强,中,弱三个耐旱等级,并筛选到30295,30253,中双6号,30703,30296,30290,30704,中油杂9号,德油4号等一批耐旱遗传资源。     

Pearl Millet Developed Deep Roots and Changed Water Sources by Competition with Intercropped Cowpea in the Semiarid Environment of Northern Namibia

abstract

The practice of intercropping pearl millet with cowpea is widespread among subsistence farmers in northern Namibia. In this region, the scarce and erratic rainfall may enhance competition for the limited soil water between intercropped plants. Trials were conducted on a field of the University of Namibia (on-station) and on a farmer’s field (off-station) to determine the effects of competition between pearl millet and cowpea on the water sources and plant growth of each crop. The deuterium analysis showed that pearl millet, intercropped with cowpea, significantly increased its dependence on the recently supplied labeled irrigation water. Intercropped cowpea also showed an increased trend of the dependence but it was not statistically significant. At the university field, intercropped pearl millet showed higher dependence on the irrigation water than monocropped pearl millet. At the farmer’s field, the dependence of intercropped pearl millet on the irrigation water was low in the pearl millet-dominant zone. In contrast, the dependence on the irrigation water was high in the cowpea-dominant zone, indicating that the dependence on the irrigation water changes according to the size of the pearl millet canopy. The water sources of cowpea did not show a significant difference at either pearl millet-dominant or cowpea-dominant zone, indicating a stable water uptake trend under competitive conditions. Competition with cowpea significantly increased the root-weight density of intercropped pearl millet in the deep soil layers, but decreased that in the shallow layers. The root-weight density of intercropped cowpea, however, was reduced in most of the soil layers. In conclusion, cowpea has a higher ability to acquire existing soil water, forcing pearl millet to develop deep roots and shift to the surface irrigation water.