厨余垃圾堆肥对烤烟土壤酶活性和细菌群落结构的影响

以滇中植烟土壤为研究对象，设置不同厨余垃圾堆肥(基肥)施用量：不施肥对照(CK)、低施肥量8 t/hm² (FWL)、中施肥量16t/hm² (FWM)、高施肥量24t/hm² (FWH)，研究厨余垃圾堆肥施用后土壤酶活性和细菌群落结构的变化特征，为厨余垃圾堆肥农田推广使用提供依据。结果表明：与CK相比，FWH处理可显著提高土壤的p H、有机碳、全氮、全磷、碱解氮、有效磷、脲酶活性、酸性磷酸酶活性、荧光素二乙酸水解酶活性(↑0.39%～89.42%)、土壤细菌OUT数目(↑12.91%)、Chao指数(↑11.20%)、Ace指数(↑11.37%)。变形菌门(Proteobacteria)的相对丰度随施肥量的增加而增加，而酸杆菌门(Acidobacteria)则相反；细菌群落的膜运输和碳水化合物代谢功能均在施肥后显著增强。脲酶活性、酸性磷酸酶活性、p H、全氮、全磷、碱解氮、有效磷指标对土壤细菌的群落组成和多样性均有影响，其中碱解氮和脲酶活性是调控菌群最主要的因子。     

Characterization of subunits encoded by SnRK1 and dissection of combinations among these subunits in sorghum (Sorghum bicolor L.)

Sucrose nonfermenting-related protein kinase 1 (SnRK1) is one of the critical serine/threonine protein kinases. It commonly mediates plant growth and development, cross-talks with metabolism processes and physiological responses to biotic or abiotic stresses. It plays a key role in distributing carbohydrates and sugar signal transporting. In the present study, eight SnRK1 coding genes were identified in sorghum (Sorghum bicolor L.) via sequences alignment, with three for α subunits (SnRK1α1 to SnRK1α3), three for β (SnRK1β1 to SnRK1β3), and one for both γ (SnRK1γ) and βγ (SnRK1βγ). These eight corresponding genes located on five chromosomes (Chr) of Chr1–3, Chr7, and Chr9 and presented collinearities to SnRK1s from maize and rice, exhibiting highly conserved domains within the same subunits from the three kinds of cereals. Expression results via qRT-PCR showed that different coding genes of SnRK1s in sorghum possessed similar expression patterns except for SnRK1α3 with a low expression level in grains and SnRK1β2 with a relatively high expression level in inflorescences. Results of subcellular localization in sorghum leaf protoplast showed that SnRK1α1/α2/α3/γ mainly located on organelles, while the rest four of SnRK1β1/β2/β3/βγ located on both membranes and some organelles. Besides, three combinations were discovered among eight SnRK1 subunits in sorghum through yeast two hybrid, including α1-β2-βγ, α2-β3-γ, and α3-β3-γ. These results provide informative references for the following functional dissection of SnRK1 subunits in sorghum.     

改良半叶法测定光合速率结果的影响因素分析

从气体交换、叶绿素荧光成像、光合产物累积对光合速率的影响等角度分析改良半叶法测定光合速率结果的影响因素,指出该方法的测定结果是光下半叶真光合速率的近似值,改良半叶法存在很多不确定性,已难以满足科研需要,但在大田生产和植物生理学教学中仍具有一定价值。