共查询到19条相似文献,搜索用时 78 毫秒
1.
为明确不同基因型小粒种咖啡的氮素吸收特性,进一步为遗传改良咖啡氮营养性状提供参考,本研究对同一氮素供应水平下20个小粒种咖啡氮素吸收效率的生理、形态机制进行研究。结果表明:大部分小粒种咖啡种质间叶绿素含量、硝酸还原酶活性(NRA)、根氮、茎氮、叶氮含量差异不显著,且叶绿素含量及NRA与叶氮、总氮累积量和氮吸收效率间相关性不显著;根长、根体积、根表面积均与根氮累积量、总氮累积量、氮吸收效率呈显著正相关;氮素在植株各器官的分配比例依次为:根氮>叶氮>茎氮;聚类分析表明,‘M13’氮吸收效率最高,为84.43%,最低为‘CATUAI’,仅为32.12%,其余种质为58.36%~43.08%。 相似文献
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
为在苗期可通过根系形态数量性状对氮高效小麦品种进行鉴别,利用营养液培养法,在正常氮(5mmol·L~(-1))和高氮(45mmol·L~(-1))处理下,研究了黄淮平原区18个主栽小麦品种苗期氮素利用效率与根系形态数量性状的关系;通过干物重和氮积累量与根系形态指标相结合的方式对供试小麦品种植株氮效率进行了综合评价,并划分不同氮效率类型。结果发现,在两种氮处理下,供试小麦品种的根干重、茎叶干重、单株干重、根氮含量、茎叶氮含量、单株氮含量、单株总根长、根总表面积、根总体积、根尖数的变异系数均大于15%,可作为氮效率评价指标。小麦的单株总根长、根总表面积、根总体积、根尖数与植株氮积累量呈显著正相关,可以作为育种早期筛选高氮效率材料的指标。不同氮效率类型的单株总根长、根总表面积、根总体积、根尖数均表现为氮高效型氮中效型氮低效型。通过逐步回归分析,建立了小麦幼苗植株氮积累量和根系形态数量性状的预测模型,拟合精度在91.91%以上。小麦不同氮效率类型间的单株总根长、根总表面积、单株根尖数的差异均达显著水平,生产上可根据小麦苗期根系的主要形态数量性状判断其氮效率高低。 相似文献
16.
Vegetative growth of branches and leaf area gain in field-grown Arabica coffee trees in Viçosa, southeastern Brazil, exhibited active and quiescent phases. Nitrogen supplementation during the cool season did not prevent growth decline, nor did it alter the overall pattern of the tree growth; however, it enabled the plants to grow faster following the quiescent growth phase. Growth was related poorly to both nitrate content and nitrate reductase activity in leaves. In roots, N-fertilization in addition to accounting for greater content of nitrate, amino acids and ammonium was also associated with the maintenance of the nitrate reductase activity, but nitrate reduction was apparently nil in leaves during most of the cool season. 相似文献
17.
《Plant Production Science》2013,16(4):374-382
AbstractSoybean yield is low in the fields with a low groundwater level during summer due to drought stress. By raising the groundwater level using Farm-Oriented Enhancing Aquatic System (FOEAS) the yield of soybean cultivar Sachiyutaka can be increased, but not that of Fukuyutaka. Here, we examined the effect of the groundwater level on root growth and its dynamics in these two cultivars. Three of the four experiments demonstrated that root elongation ceased just below groundwater level in both cultivars. However, when the groundwater level was kept at 35 cm or deeper, the root growth at an early growth stage was more vigorous at a deeper layer in Fukuyutaka than in Sachiyutaka, but at the mid-growth stage root growth in Sachiyutaka became similar to or exceeded that of Fukuyutaka. These results indicated that the optimum control technique for the groundwater level differed with the cultivar. The groundwater level for Sachiyutaka should be kept relatively high at an early growth stage. Further studies will be needed to clarify the optimum control technique for maximizing the yield of Fukuyutaka that have a fast root growth at an early growth stage. 相似文献
18.
橡胶叶水浸提液对花生幼苗早期根系形态及其生理特性的影响 总被引:1,自引:0,他引:1
为深入理解橡胶树的化感抑制作用,采用适当浓度的橡胶叶水浸提液处理刚萌动的花生种子10 d,测定花生幼苗早期根系形态及其生理指标。结果表明:橡胶叶水浸提液能显著降低花生幼苗胚根长度、苗高、根鲜重、地上部鲜重以及根冠比,对根生长的抑制作用比地上部强烈;能显著降低根系总长、根表面积、根体积和根尖数,但对根平均直径有轻微的促进作用,与对照相比,差异不显著;能显著降低根系SOD、POD、CAT活性、可溶性蛋白质、可溶性糖、脯氨酸含量以及根系活力,却明显增加根系MDA含量和相对电导率。说明橡胶叶水浸提液可通过破坏花生幼苗的抗氧化防御机制,降低其渗透调节能力,减少根系的吸收面积,抑制根系的吸收活性来抑制花生幼苗的生长。 相似文献