Moso bamboo expansion into a broadleaved forest alters the dominant soil organic carbon source

Both microbes and plants contribute to soil organic carbon (SOC) formation and retention, but their roles in controlling SOC dynamics in forest soils under Moso bamboo (Phyllostachys edulis) expansion remain unclear. Here, amino sugars and lignin monomers were measured to represent microbial necromass and plant-derived components, respectively. The observed decline in both amino sugars and lignin monomers during Moso bamboo expansion indicates a reduction in microbial necromass and recalcitrant plant contributions to SOC composition. This could be attributed to a limitation of microbial substrates and proliferation caused by the reduced litter inputs resulting from the expansion. The proportion of microbial necromass contributing to the SOC pool increased, but that of lignin monomers decreased, as SOC content decreased with Moso bamboo expansion. This suggests that the decrease of SOC during bamboo expansion was mainly due to the reduction of lignin, while the increased contribution of microbial-derived carbon to SOC may serve to improve SOC stability. Our study sheds light on the altered SOC source inputs resulting from Moso bamboo expansion and emphasizes the need for sustainable forestry management practices that differentiate between microbial- and plant-derived carbon pools.     

浙江临安应对“新冠肺炎”疫情促进雷竹生产的措施与思考

雷竹笋是江浙一带城市居民的菜篮子、当地农村百姓的钱袋子。雷竹笋产业是浙江临安区农业的重要支柱产业。2020年春节后一场突如其来的“新冠肺炎”疫情严重影响了雷竹笋的正常生产与经营活动,给笋农造成很大损失。文章分析了新冠肺炎疫情对雷竹生产造成的影响以及为应对疫情所采取的措施,在此基础上针对雷竹笋竹产业如何应对突发事件提出了建议。     

土壤中一株溶磷青霉菌的分离鉴定及其应用效果研究

从土壤中筛选出一株能在以 Ca 3(PO4)2为无机磷源的平板上形成透明圈,且在以 FePO 4和 AlPO 4为无机磷源的平板上不能产生肉眼可见的溶磷圈的青霉菌株( Penicillium brocae)P6。在液体培养条件下,P6能够高效溶解 Ca 3(PO4)2,对 FePO 4和 AlPO 4也具有一定的溶解能力,但远不如 Ca 3(PO4)2,氮源种类(NH 4+/NO3 )对 P6的溶磷能力有一定的影响。检测 P6发酵液 pH发现随培养时间延长,pH总体呈降低趋势,通过高效液相色谱(HPLC)从发酵液中检测出草酸、苹果酸、乳酸和柠檬酸,而有机酸的含量和 Ca 3(PO4)2的溶解量之间并不存在相关性。此外,栽培试验表明,P6对小白菜( Brassica chinensis)具有促生作用,最优处理T2(钙镁磷肥 + P6孢子悬液)的鲜重、干重以及根际土壤有效磷含量比对照 CK1(水)、CK2(钙镁磷肥)和处理 T1(P6孢子悬液)均有显著增加。虽然 T1处理的上述指标均不及 CK2处理,但在鲜重和根际土壤有效磷含量上要优于 CK1处理,说明了 P6有提高土壤有效磷含量,促进小白菜生长以及提高钙镁磷肥肥效的作用。     

Microbial community dynamics and their contributions to organic acid production during the early stage of the ensiling of Napier grass (Pennisetum purpureum)

The study aimed to disclose the microbial community dynamics and their contributions to organic acid production during the ensiling of Napier grass. Napier grass was harvested at the vegetative growth phase and ensiled for 30 days. Three silos were opened after 1, 2, 3, 5, 7, 14, and 30 days of ensiling respectively. The intensive fermentation was observed during the initial stage of ensiling, indicated by lower pH (<4.0) on d 2 of ensiling. Lactic acid (LA) was the primary fermentation product, although acetic acid (AA) concentration rapidly increased and LA/AA concentration gradually decreased after 3 days of ensiling. The ethanol concentration was already 11.8 g/kg DM on d 1 of ensiling and then remained stable until the end of ensiling. Lactococcus was the predominant genus during the initial 2 days of ensiling, and then, it was gradually replaced by Lactobacillus. The increase in ammonia nitrogen and butyric acid concentration after 7 days of ensiling was attributed to the growth of Clostridia, which is favored by the high moisture concentration in the Napier grass. The natural ensiling of Napier grass displayed LA-type fermentation and was dominated by the fermentation of Lactobacillus and Lactococcus. Lactobacillus is mainly responsible for the LA production during the ensiling of Napier grass.     

毛竹中黄酮-C-糖基转移酶基因的克隆和生物信息学分析

糖基转移酶是催化黄酮糖苷形成的关键酶。黄酮糖苷类化合物具有抗氧化、清除自由基、调节血脂和血糖等生理作用。基于毛竹基因库测序的完成,本研究通过RT-PCR技术首次获得一条完整的毛竹黄酮-C-糖基转移酶基因开放阅读框,将其命名为PeCGT,其基因的序列长度是1342 bp。对其编码蛋白的理化性质、保守结构域以及二级结构和空间结构等进行了生物信息学分析。结果表明:PeCGT基因编码的蛋白含有447个氨基酸,分子量是47.76 kD,理论等电点为4.91,酸性氨基酸(Asp+Glu)个数为54,碱性氨基酸(Arg+Lys)个数为35。PeCGT蛋白是疏水型蛋白,不存在信号肽,存在于线粒体中。结构域预测分析结果表明,PeCGT编码的氨基酸序列具有明显的糖基转移酶特征的保守域结构PSPG。通过同源性分析,其与乌拉图小麦(Triticum urartu)、节节麦(Aegilops tauschii subsp.Tauschii)和二穗短柄草(Brachypodium distachyonhiihii)具有较高的同源性。实时荧光定量PCR结果表明:PeCGT基因在叶中的表达量最高,在根中几乎不表达,在茎中有部分表达。此研究结果为以后毛竹黄酮-C-糖基转移酶的表达和功能鉴定提供了一定的帮助。     

Evaluation of the contribution of teosinte to the improvement of agronomic,grain quality and yield traits in maize (Zea mays)

Teosinte, an ancestor to modern maize, displays an excellent performance regarding resistance to stress, but its yield potential has rarely been reported. To evaluate the potential contribution of teosinte to maize improvement, two maize–teosinte backcrossed recombination inbred line (RIL) populations and their corresponding test-cross hybrids were planted for trait assessment. In RN and ZP RIL populations, the average coefficients of variation of 31 agronomic traits were 9.14% (Range, 0.38%‒25.21%) and 6.85% (Range, 0.55%‒27.73%), respectively. The correlation coefficients of 13 common shared traits between RIL populations and test-cross hybrid populations ranged from 0.10 to 0.60 and from 0.06 to 0.72, respectively. A total of 39 and 3 recombined inbred lines, and 29 and 47 test-cross hybrids exhibited higher yields than their checks (RP125, Zheng58, CD189 and ZD958) with the BLUP data, respectively. Furthermore, four test-cross hybrids including RN034/SCML1950, ZP068/Chang7-2, ZP079/Chang7-2 and ZP122/Chang7-2 showed a more stable yield performance, with yield gains of +7.07%, +3.64%, +5.83% and +3.82% over checks, respectively. In conclusion, teosinte could serve as an alien germplasm for maize breeding.     

不同防腐剂处理马尾松边材防腐性能研究

利用扫描电镜(SEM)分析了马尾松边材素样以及6种防腐剂处理马尾松边材在被褐腐菌侵染后的降解情况,采用同步热分析(TGA-DSC)研究了试样热解特性、各反应阶段热动力学参数等。研究表明:当热解温度升高到600℃时,各试样失重率从小到大依次为10%丙酮<10%蒸馏水<马尾松素样<4%樟脑<10%乙酸乙酯<10%甲醇<4%氨溶烷基铜铵(ACQ),最大失重量越大则对应试样防腐剂的防腐效果越好。各试样的热解在低温区(260~380℃)和高温区(380~600℃)分别满足一级和二级反应动力学方程。各试样活化能从一级反应到二级反应阶段均出现不同程度减小。试样浸渍的防腐剂防腐效果越好,其褐腐后的纤维素含量保留得就越多,则对应试样的一级热解反应活化能越高。     

玉米苗期抗旱性状的主基因和多基因遗传分析

为了解玉米苗期抗旱遗传规律,以抗旱玉米自交系'81162'和干旱敏感自交系'沈503'构建P1、P2、F1、B1、B2、F2 6世代群体,采用数量性状的主基因+多基因遗传模型分析方法对苗期玉米苗高、根鲜重、地上鲜重、根干重、地上干重、根长、鲜重根冠比、干重根冠比性状的抗旱系数进行遗传分析.结果表明,苗高、根鲜重、地上鲜...