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玉米自交系对镰刀菌茎腐病的抗性存在着广泛的遗传变异(gcv=18.37%),并具有较高的遗传力(h~2=84.87%)。随着玉米年龄的增大,髓组织密度与髓组织含糖量间的相关系数的绝对值逐渐增大,在抽雄后19天和28天,正相关性达到了极显著水平。病害发展过程中各时期的髓组织密度对茎腐病级别的总效应和直接效应皆为负值;不同时期的髓组织 相似文献
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K. Norell 《Computers and Electronics in Agriculture》2011,75(2):231-237
One of the essential requirements of current agricultural practice is the need to evolve towards crop techniques that make better use of productive factors behaving in sustainable and environmentally respectful ways. Pest control is one of the most important problems to take into account, due to the significant production losses that pests may cause. The Integrated Production for olive crop defines a set of rules that has to be followed in order to ensure a production of higher quality, and promotes an environmentally respectful model of Olive cultivation. This work presents SAIFA (spanish acronym for Sistema de Alerta e Información Fitosanitaria Andaluz - Andalusian Phitosanitary Information and Alert System) a web-based information system which allows monitoring the Integrated Production for the olive crop in Andalusia, Spain. SAIFA has been built as a tool to assist agricultural technicians to comply with the quality standards of Integrated Production, and to help decision makers to choose the actions to be performed in the crop. Also, it assists coordinators to choose an Integrated Production strategy applicable for the whole region with the main objective of ensuring the safety of crops and reporting the current phitosanitary state to the authorities. 相似文献
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《Plant Production Science》2013,16(3):184-189
AbstractCassava (Manihot esculenta Crantz) can produce a high crop yield even in an environment with irregular rains. This is mainly attributed to its abilities to maintain leaf area under drought conditions and rapidly regrow after rain. In this study, we investigated the mechanism of leaf maintenance under water deficits through measurement of photosynthetic rate and water potential changes in leaves. The cassava plants were grown in pots and exposed to water deficits, and the diurnal changes in water potentials, rates of photosynthesis and transpiration and stomatal conductance were measured. The relationship between leaf water potential (ψW) and photosynthetic rate with decreasing soil water, and osmotic adjustment were also investigated. With respect to water supply in leaves, the movement of water in plants was measured using stem heat balance. Under water deficits, photosynthesis occurred only in the early morning. The water loss was reduced by stomatal closure in the mid-day. This was attributed to the complete closure of the stornata during the decrease in ψW to a range between –1.0 and –1.4 MPa. Furthermore, the firm stomatal closure is caused by the consistency of osmotic potential under decreases in soil water, i.e., to a lack of osmotic adjustment. Water stored in the pith parenchyma of stem flowed into leaves in the morning. From these results, we conclude that cassava can consistently maintain an adequate water level in leaves via water storage and the sensitivity of stornata to water deficits, thereby avoiding leaf dehydration. 相似文献
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The by-products of sunflower production were characterized. The sunflower heads contain a strong smelling essential oil (EO) (0.2%) and pectins (22%). The galacturonic acid (GA.A.) content of the pectins depends on the extraction conditions (water-soluble pectins: 67%, soluble in ammonium oxalate/oxalic acid: 74%, in hydrochloric acid: 33%). They are all slightly methylated (degree of methylation (DM) <20%). The stalks may be readily separated into two parts: fiber (external part, 90%) and the pith (internal part, 10%). The mechanical properties of paper pulp obtained by thermomechanical treatment in a twin-screw extruder of the whole stalks or depithed stems were investigated. The pulps had high values of ring crush test (RCT) and concora medium test (CMT), which make them suitable for the manufacture of cardboard. Low-density materials can be also shaped with ground pith. The role of water-soluble substances in the cohesion of these materials is discussed. Its mechanical properties, which are comparable to those of polystyrene, were determined. They may find application in the packaging and packing industries. 相似文献
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油菜薹茎段髓部原生质体培养再生植株 总被引:2,自引:0,他引:2
以油菜品种“蜀杂6号”的薹茎段髓部为材料分离原生质体,产量一般在每g鲜重2×10~6个左右。在每L附加1.5mgBA、0.4mgNAA、1.5mg2,4-D、200mg水解酪蛋白、250mg木糖、0.3M蔗糖和0.1M葡萄糖的Nitsch培养基中,对原生质体进行液体浅层静置培养。2~7天内原生质体出现第一次分裂,分裂频率最高可达49.2%。培养15天后逐渐形成肉眼可见的小愈伤组织。21天时将培养基改换成每L附加2mgBA、0.2mg 2,4-D和3%蔗糖的MS扩增培养基,45天后可形成5mm左右的愈伤组织。大于2mm的愈伤组织可在每L含有1.0mgBA/3.0mgZT和0.1mgNAA的MS琼脂培养基上分化出芽,分化频率可达36.7%。在1/2MS无激素培养基中,1cm左右的分化芽有85.9%生根,形成完整的植株。 相似文献
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