为揭示蒙古冰草对氮添加的响应机制,设置5个氮添加水平(0,0.8,1.6,2.4,4.0 g N·m^(-2)·a^(-1))对蒙古冰草进行为期2个月处理后,测定根系、叶片中可溶性糖、淀粉、碳(C)、氮(N)、磷(P)的含量,分析氮添加对蒙古冰草叶片、根系非结构性碳水化合物(NSCs)与C、N、P含量及其化学计量特征关系的影响。结果表明:2.4 g N·m^(-2)·a^(-1)的氮素添加显著提高了蒙古冰草叶片、根系NSCs含量与C、N、P含量,且不同器官的响应有显著差异性(P<0.05)。叶片NSCs含量与叶片N、可溶性糖、淀粉含量、C/P及N/P呈显著正相关关系,与叶片P含量、C/N呈显著负相关关系(P<0.05);根系NSCs含量与根系C、N、C/P、N/P、可溶性糖和淀粉含量呈显著正相关(P<0.05)。叶片与根系N/P是影响蒙古冰草体内可溶性糖积累的主要因子;根系N含量与叶片P含量共同影响淀粉含量;叶片P含量、根系N含量及根系N/P综合影响NSCs含量。综上,适量的氮添加会缓解研究区蒙古冰草的N限制,促进NSCs合成,而大量氮添加会导致N、P比例失衡,加剧P限制。因此,未来气候变化背景下蒙古冰草人工草地种植或退化草地恢复管理过程中需要考虑优化氮肥施用量与适当的磷添加。
Taking Malus pumila Mill, Cv. ‘Jinguan＇ as test matedal, the storage quality of the apples under the different storage conditions of plastic membrane atmosphere storage （MAP）, fruit wax coating, chitosan treatment with different calcium fertilizers were studied. The results showed that different storage modes inhibited the fruit rotting and weight loss, delayed the decrease of fruit hardness and titratable acid content, reduced the soluble solid content, inhibited the degradation of vitamin C. The suitable treatment had good effect on preservation of apple fruits, in which 1% chitosan treatment had the best effect.
