K + nutrition significantly enhanced the fresh and the dry weight of shoots and roots whether under control ( 0 mmol / l nacl ) or under nacl stress ( 100 , 400 mmol / l ) Of几） ， k “营养明显增加了碱蓬地上部分和根的鲜重，地上部分和根的于重也都随k十浓度的增加而增加。
So it is considered that root which act as a sort of barrier retards the upwards transform of heavy metal such as lead , arsenic and cadmium , and protects the overground parts of the crop from toxin 因此认为根作为一种屏障使重金属铅、砷和镉难于向上部分迁移，使地上部分免受其害。
For a given rice variety , the crop harvest index , which is calculated by the grain yield divided by total dry matter produced above ground , may vary with crop management practices used 对于给定的水稻品种，作物收获指数（由籽粒产量除以地上部分总干物重求得）可能随作物管理措施不同而变化。
( 3 ) according to the changes of water content , oxygen free radical content and surperoxide dismutase activity , seedlings of sorghum showed some adaptability to lower stress of salinity and alkalinity ( 3 )由地上部分含水量、氧自山基含量及sod活性变化可得，高粱幼苗在受较低水平的混合盐碱胁迫时具有一定的适应性。
The effects of fire on ecosystems are complex , ranging from the reduction or elimination of aboveground biomass to impacts on belowground physical , chemical and microbial mediated processes and fine root 火对生态系统的影响是复杂的，范围也很广，从减少地上部分生物量到对地下部分物理性质、化学性质、微生物降解过程和细根系的生长。
Plant samples above ground were taken respectively at seedling stage , maximum tillering stage , full heading stage and full ripe stage for n , p , k , si content analysis carried out according to " routine analysis method for soil agro - chemistry " 在苗期、最大分蘖期、齐穗期和完熟期分别采取地上部分植株样本，按照“土壤农化常规分析法”化验氮、磷、钾、硅含量。
2 effect of k + nutrition and nacl stress on the growth and k + content of suaeda salsa plants the results showed that the increase in growth of suaeda salsa plant was mainly due to the increase of shoots 二拉营养和naci胁迫对碱蓬生长和k ”含量的效应碱蓬的生长主要以地上部分为主。 k “营养供给缺乏时，碱蓬分枝较少，长时间缺k ”培养，叶片瘦弱，叶黄，老叶受害明显。
Results show that the growth of plants is limited , growth of root is enhanced , water consumption is reduced , water use efficiency increase apparently , yield has little reduce when reducing irrigation water and detaining irrigation time properly 结果显示：分蘖拔节期适当减少灌水量并推迟灌水时间，能抑制春小麦地上部分的生长，促进根系生长，减少总耗水量，提高水分利用率。
In aerial parts of the plant the outer wall of the epidermis is usually covered by a waxy cuticle that prevents desiccation , protects the underlying cells from mechanical damage , and increases protection against fungi , bacteria , etc 植物地上部分的表皮的最外层通常覆盖一层蜡质角质层，起保护作用以防止过渡蒸腾，并使下方的细胞免于机械损伤，同时增加对真菌、细菌等的防御能力。
We have identified a nucleotide sequence from ests ( expressed sepuence tagged ) acquired fromzap - cdna library of thellungiella salsuginea treated with 200mmol . l - 1 nacl and analyzed its nucleotide sequence characterization , gene organization , and differential expression under salt stress 本实验从200mmol . l ~ ( - 1 ) nacl处理的小盐芥地上部分构建的zap - cdna文库中克隆了编码硫氧还蛋白的基因序列。
