顶棚温湿度调节晾房对马里兰烟晾制的影响

马里兰烟对晾制温湿度环境条件要求较苛刻,不适宜的环境条件易造成含青烟或霉烂烟,严重影响烟叶质量。因此,对马里兰烟调制设施和晾制技术进行了研究。结果表明,顶棚温湿度调节晾房较水泥瓦等上盖标准晾房日间温度高1~2℃,晾房内相对湿度低5%~10%,且保温保湿时间较长,有利于马里兰烟凋萎变色,烟叶晾制质量较好;其结合两段式干筋棚分片上绳晾制技术效果更佳,可以有效减少烟叶含青和霉烂现象,提高上中等烟比例10%左右。     

白肋烟和马里兰烟叶绿素酶活性测定及其基因表达的实时定量PCR分析

白肋烟是普通烟草（Nicotiana tobacum. L）马里兰烟的缺绿突变类型。本研究在测定比较了白肋烟和马里兰烟叶片叶绿素酶活性的基础上,以18s rRNA为内参基因,采用实时定量PCR技术检测分析了成株期白肋烟和马里兰烟叶片中叶绿素酶基因的表达情况。酶活性测定结果发现白肋烟Burley21和马里兰烟Md609叶片中的叶绿素酶活性分别为525.17 nmol/(g?h)和257.60 nmol/(g?h),前者为后者的2.03倍。实时定量PCR检测结果表明,Burley21中叶绿素酶基因相对表达量为Md609中的3.01倍。这表明白肋型烟草叶片中叶绿素酶活性及其基因表达量的升高,可能导致了叶绿素的快速降解,从而使白肋烟叶片呈现缺绿黄化性状表现。     

不同调制方法对烟草烟碱转化及TSNA的影响

为进一步明确调制方式对不同品种(系)烟草烟碱转化和特有亚硝胺(TSNA)的影响,采用裂区试验设计,以白肋烟[B37LC(低烟碱转化)品系、B37HC(高烟碱转化)品系]、马里兰烟[Md609LC(低烟碱转化)品系、Md609HC(高烟碱转化)品系]、烤烟(‘云烟87’、‘K326’)和晒烟(‘深色公会晒黄烟’、‘浅色公会晒黄烟’)等4种烟草类型的8份材料为主处理,烤制、晾制和晒制3种调制方法为副处理,进行了生物碱和4种TSNA含量检测与研究。结果表明:品种(系)是影响生物碱含量、烟碱转化率和4种TSNA含量的主要因素,N?亚硝基降烟碱(NNN)是4种烟草类型的主要TNSA,所占比例在54.35%~97.36%。不同烟草类型中以白肋烟、马里兰的HC品系与LC品系间差异最大,其中LC品系的NNN含量比HC品系下降90.93%和91.54%。3种调制方法中,烟碱含量为烤制晒制晾制,降烟碱及烟碱转化率则为晾制晒制烤制;除N-亚硝基假木贼碱(NAB)含量烤制显著高于晾制外,NNN、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)、N-亚硝基新烟碱(NAT)及TSNA总量均为晾制晒制烤制,差异达显著或极显著水平;调制方法对白肋烟、马里兰烟的HC品系影响最大,对LC品系影响最小。综合认为:在烟叶特别是白肋烟、马里兰烟生产上积极推广烟碱转化率低的品种,同时努力改善调制条件、改进调制工艺是降低烟叶TSNA含量、提高烟叶安全性的关键措施。     

马里兰烟空茎病防治技术研究

为探索适宜湖北省五峰烟区马里兰烟空茎病的防治方法,从移栽方式、药剂施用、施肥配比等多方面开展了马里兰烟空茎病的田间防治试验.结果表明,膜下移栽和井窖式移栽马里兰烟空茎病的病情指数较常规大田移栽分别降低了7.84和9.00,而膜上移栽效果不佳.在参试药剂中,凡士林涂抹、甲基托布津750倍喷雾效果较好,防效分别为82.18％、82.95％,农用链霉素2 000倍喷雾和塞菌铜600倍喷雾效果略差,防效分别为80.02％和79.76％;农用链霉素40倍涂抹防治效果不理想,仅为34.87％.在施纯氮180 kg/hm2时,空茎病的病情指数最低,为0.83,此时适宜的氮磷、氮钾配比分别为1∶1、1∶3.在大田生产中,采用膜下移栽和井窖式移栽方式,通过合理施肥,再配合甲基托布津750倍和农用链霉素2 000倍喷雾的化学防治手段,可以达到综合防治马里兰烟空茎病的目的.     

五峰马里兰烟草花叶病及病毒检测

为了摸清五峰马里兰烟草花叶病毒病的发生情况,采用田间调查和实验室RT-PCR技术进行了TMV、CMV和PVY的感染情况检测。结果表明,在五峰马里兰烟区发生的烟草花叶病常表现为TMV、CMV与PVY的复合感染,复合感染率为50%。其中,以TMV感染为主,检出率为100%;其次是CMV感染,检出率为50%;然后是PVY感染,检出率为40%。     

马里兰烟试验示范基地的SWOT分析及对策

采用SWOT战略分析法,对影响宜昌五峰马里兰烟发展的内部优势和劣势,以及所面临的机遇和威胁等因素进行综合分析,挖掘其潜在竞争优势,提出提升宜昌五峰马里兰烟研究中心核心竞争力的相应策略,对宜昌烟草企业未来经营发展战略具有借鉴意义     

马里兰烟新品种五峰1号的选育及特征特性

[目的]为马里兰烟新品种五峰1号的推广种植提供科学依据。[方法]五峰1号是利用马里兰烟609(Md609)系统选育的马里兰烟新品种,介绍其选育经过,分析其特征特性。[结果]该品种株式筒形,株高较高,叶片长椭圆形,有效叶较多,大田生育期适中;生长势强,产量适宜,产值较高;抗黑胫病和根黑腐病,中抗赤星病,易感花叶病毒病、空茎病,较耐旱,适应范围较广。原烟叶片结构疏松,身份适中,颜色红黄,光泽明亮,外观质量好。总糖、还原糖含量低,总氮、烟碱含量适宜,钾含量高,氯离子含量低,化学成分协调,香型风格显著,香气质好,香气量较足,燃烧性强,工业利用价值高。[结论]五峰1号综合性状表现优良,适宜在湖北宜昌地区种植。     

Diversity declines in Microstegium vimineum (Japanese stiltgrass) patches

The spread of invasive plant species and their impacts on plant communities have received international attention as global trade and global environmental change enhance the colonization and establishment of introduced species and threaten the integrity of native ecosystems. Because introduced species vary in their impact, studying the relationship between invasion and native communities is necessary to guide allocation of finite management resources. By studying adjacent pairs of invaded and uninvaded plots across an eastern United States forested landscape, we demonstrate Microstegium vimineum was associated with local declines in species richness and cover of native species. Negative impacts of M. vimineum on species richness did not emerge until August when M. vimineum cover and height were greatest, highlighting the value of following study subjects through the growing season. In contrast, native species cover was already lower in invaded plots early in the growing season. M. vimineum invasion was not the only important driver of species richness and community composition within the study region; abiotic environmental gradients, such as soil nitrate concentration and pH, across the six study sites were also important in affecting species richness and cover, but lessened in explanatory power through the growing season. We conclude that M. vimineum has effects on community structure that may have long-term consequences for biodiversity. Studies which track sites through time and consider multiple scales are required as invaders impact multiple biotic and abiotic factors operating at different spatial and temporal scales.     

五峰县马里兰烟赤星病防治技术研究

[目的]探讨适宜湖北省五峰烟区马里兰烟赤星病防治方法。[方法]从不同海拔、抗性品种、移栽方式、药剂施用几个方面研究了马里兰烟赤星病的防治技术。[结果]低山烟区赤星病害发病率较低。在抗病性接种鉴定中,五峰1号、Md872、Md609均表现为中抗烟草赤星病。膜下移栽和井窖式移栽的赤星病病情指数较对照常规大田移栽分别降低8.81和8.98。在参试药剂中,塞菌铜600倍、甲基托布津750倍对赤星病的防治效果较好,分别达到98.41%和98.58%;农用链霉素2 000倍和菌核净600倍的防治效果略差,分别为96.48%和97.32%。[结论]为马里兰烟赤星病的综合防治提供了参考。     

Electron donors and acceptors influence anaerobic soil organic matter mineralization in tidal marshes

Anaerobic decomposition in wetland soils is carried out by several interacting microbial processes that influence carbon storage and greenhouse gas emissions. To understand the role of wetlands in the global carbon cycle, it is critical to understand how differences in both electron donor (i.e., organic carbon) and terminal electron acceptor (TEA) availability influence anaerobic mineralization of soil organic matter. In this study we manipulated electron donors and acceptors to examine how these factors influence total rates of carbon mineralization and the pathways of microbial respiration (e.g., sulfate reduction versus methanogenesis). Using a field-based reciprocal transplant of soils from brackish and freshwater tidal marshes, in conjunction with laboratory amendments of TEAs, we examined how rates of organic carbon mineralization changed when soils with different carbon contents were exposed to different TEAs. Total mineralization (the sum of CO₂ + CH₄ produced) on a per gram soil basis was greater in the brackish marsh soils, which had higher soil organic matter content; however, on a per gram carbon basis, mineralization was greater in the freshwater soils, suggesting that the quality of carbon inputs from the freshwater plants was higher. Overall anaerobic metabolism was higher for both soil types incubated at the brackish site where SO₄²⁻ was the dominant TEA. When soils were amended with TEAs in the laboratory, more thermodynamically favorable respiration pathways typically resulted in greater organic matter mineralization (Fe(III) respiration > SO₄²⁻ reduction > methanogenesis). These results suggest that both electron donors and acceptors play important roles in regulating anaerobic microbial mineralization of soil organic matter.