甘蔗纤维固定灵芝菌丝及其在液体发酵中的应用

以甘蔗纤维作为灵芝菌丝固定载体,通过扫描电子显微镜观察确定载体固定时间,通过液体发酵灵芝菌丝球大小形态、生物量、胞外多糖和胞外三萜含量确定载体形状、大小与数量。结果表明,灵芝菌丝在载体上固定时间为7d,载体为1.5cm×1.5cm（直径×高度）的圆柱体小块（Y1.5）,接种数量6块,可连续稳定发酵7代。以甘蔗纤维固定发酵制备灵芝液体发酵种子,发酵后菌丝球大小均一,生物量、胞外多糖含量和三萜含量分别提高78%、84%和60%。     

鉴定转Bt甘蔗抗条螟的方法

通过采集蔗田条螟Proceras venosatus Walker的蛹,在室内可控条件下进行羽化、交配、产卵、孵化的方式获得虫源,并将初孵幼虫接于检疫温室桶栽的13个转Bt基因甘蔗品系的心叶上,7 d后调查幼虫的生长死亡情况以及甘蔗受害程度.结果表明,综合幼虫的生长死亡情况和甘蔗受害程度二项指标,能更准确评价甘蔗的抗虫...     

Occupancy and abundance of wintering birds in a dynamic agricultural landscape

Assessing wildlife management action requires monitoring populations, and abundance often is the parameter monitored. Recent methodological advances have enabled estimation of mean abundance within a habitat using presence–absence or count data obtained via repeated visits to a sample of sites. These methods assume populations are closed and intuitively assume habitats within sites change little during a field season. However, many habitats are highly variable over short periods. We developed a variation of existing occupancy and abundance models that allows for extreme spatio-temporal differences in habitat, and resulting changes in wildlife abundance, among sites and among visits to a site within a field season. We conducted our study in sugarcane habitat within the Everglades Agricultural Area southeast of Lake Okeechobee in south Florida. We counted wintering birds, primarily passerines, within 245 sites usually 5 times at each site during December 2006–March 2007. We estimated occupancy and mean abundance of birds in 6 vegetation states during the sugarcane harvest and allowed these parameters to vary temporally or spatially within a vegetation state. Occupancy and mean abundance of the common yellowthroat (Geothlypis trichas) was affected by structure of sugarcane and uncultivated edge vegetation (occupancy = 1.00 [ = 0.96–1.00] and mean abundance = 7.9 [ = 3.2–19.5] in tall sugarcane with tall edge vegetation versus 0.20 [ = 0.04–0.71] and 0.22 [ = 0.04–1.2], respectively, in short sugarcane with short edge vegetation in one half of the study area). Occupancy and mean abundance of palm warblers (Dendroica palmarum) were constant (occupancy = 1.00, = 0.69–1.00; mean abundance = 18, = 1–270). Our model may enable wildlife managers to assess rigorously effects of future edge habitat management on avian distribution and abundance within agricultural landscapes during winter or the breeding season. The model may also help wildlife managers make similar management decisions involving other dynamic habitats such as wetlands, prairies, and even forested areas if forest management or fires occur during the field season. © 2011 The Wildlife Society.     

Effect of agronomic factors on the spatial distribution of greyback canegrub, Dermolepida albohirtum (Waterhouse) (Coleoptera: Scarabaeidae), in sugarcane in the Burdekin River Irrigation Area

Abstract A series of studies were undertaken examining the factors that impact on the spatial distribution of greyback canegrub infestations in sugarcane in the Burdekin region of Queensland. Historic records of damage by greyback canegrub showed that sugarcane blocks planted or harvested earlier than surrounding blocks were more likely to be damaged than blocks planted or harvested later. The derived hypothesis that sugarcane height may be the primary determinant of where damage occurs was confirmed in field studies. The tallest sugarcane blocks at the time of oviposition consistently had the highest grub populations. There was no difference in the distribution of damage between the cultivars Q96 and Q117 and the age of these crops also had no impact. The finding that sugarcane height is the primary determinant of where damage occurs on Burdekin farms opens the possibility of using it as a tool to manipulate where canegrubs oviposit and the development of a range of associated cultural control strategies.     

甘蔗不同部位的固氮酶活性检测

比较巴西2个固氮甘蔗品种‘B1’、‘B8’的叶片、主脉、叶鞘、茎、根和根际周围固氮酶活性的结果表明:茎、根、根际周围的固氮酶活性较高。     

Field performance of transgenic sugarcane produced using Agrobacterium and biolistics methods

Future genetic improvement of sugarcane depends, in part, on the ability to produce high‐yielding transgenic cultivars with improved traits such as herbicide and insect resistance. Here, transgenic sugarcane plants generated by different transformation methods were assessed for field performance over 3 years. Agrobacterium‐mediated (Agro) transgenic events (35) were produced using four different Agrobacterium tumefaciens strains, while biolistic (Biol) transgenic events (48) were produced using either minimal linearized DNA (LDNA) transgene cassettes with 5′, 3′ or blunt ends or whole circular plasmid (PDNA) vectors containing the same transgenes. A combined analysis showed a reduction in growth and cane yield in Biol, Agro as well as untransformed tissue culture (TC) events, compared with the parent clone (PC) Q117 (no transformation or tissue culture) in the plant, first ratoon and second ratoon crops. However, when individual events were analysed separately, yields of some transgenic events from both Agro and Biol were comparable to PC, suggesting that either transformation method can produce commercially suitable clones. Interestingly, a greater percentage of Biol transformants were similar to PC for growth and yield than Agro clones. Crop ratoonability and sugar yield components (Brix%, Pol%, and commercial cane sugar (CCS)) were unaffected by transformation or tissue culture. Transgene expression remained stable over different crop cycles and increased with plant maturity. Transgene copy number did not influence transgene expression, and both transformation methods produced low transgene copy number events. No consistent pattern of genetic changes was detected in the test population using three DNA fingerprinting techniques.     

甘蔗宿根萌发期內源激素变化与其宿根性的关系

采用酶联免疫法和茎基部取样的方式,以强宿根甘蔗品种‘新台糖22号’为对照,通过田间试验研究了同一组合(‘粤糖97-20’×ROC25)杂交后代分离产生的强宿根甘蔗品(种)系(‘云蔗06-407’、‘云蔗06-415’)和弱宿根甘蔗品(种)系(‘云蔗06-408’、‘云蔗06-416’)宿根萌发期内源激素含量的变化与甘蔗宿根性的关系。结果显示:(1)宿根萌发过程中,强宿根与弱宿根甘蔗茎基部IAA含量、ZR含量和ZR/IAA比值的变化波动大,但差异不显著。(2)强宿根与弱宿根甘蔗茎基部GA3和ABA含量、IAA/ABA和GA3/ABA比值的变化差异较大,其中ABA含量、IAA/ABA和GA3/ABA比值的差异显著,是与甘蔗宿根性关系密切的3个重要参数。(3)强宿根甘蔗ABA含量高于弱宿根甘蔗,而其IAA/ABA和GA3/ABA比值小于弱宿根甘蔗,且IAA/ABA和GA3/ABA比值随甘蔗宿根性的减弱而增大。研究认为,在宿根萌发期,甘蔗宿根性越强,ABA含量越高,IAA/ABA和GA3/ABA比值越小;而这3个重要参数均与ABA有关,进行甘蔗宿根性评价应着重参考ABA含量,同时结合IAA/ABA和GA3/ABA比值再进行深入分析鉴定。     

Enhancing the enzymatic digestibility of sugarcane bagasse through the application of an ionic liquid in combination with an acid catalyst

Various ionic liquids have been identified as effective pretreatment solvents that can enhance the cellulose digestibility of lignocellulose by removing lignin, one of the main factors contributing to the recalcitrant nature of lignocellulose. 1-Butyl-3-methylimidazolium methylsulfate ([BMiM]MeSO(4)) is a potential delignification reagent, hence its application as a pretreatment solvent for sugarcane bagasse (SB) was investigated. The study also evaluated the benefit of an acid catalyst (i.e., H(2) SO(4)) and the effect of pretreatment conditions, which varied within a time and temperature range of 0-240 min and 50-150°C, respectively. The use of an acid catalyst contributed to a more digestible solid and a higher degree of delignification. However, the [BMiM]MeSO(4)-H(2) SO(4) combination failed to produce a fully digestible solid, as a maximum cellulose digestibility of 77% (w/w) was obtained at the optimum pretreatment condition of 125°C for 120 min. Furthermore, up to half of the lignin content could be extracted during pretreatment, while simultaneously extensive, sometimes complete, removal of xylan, the presence of which, also hampers cellulose digestibility. Hence, [BMiM]MeSO(4) has been identified an effective pretreatment solvent for SB as the application thereof both significantly improved digestibility, and simultaneously removed two of the main factors contributing to the recalcitrant nature of lignocellulose. As xylan and lignin have potential value as precursor chemicals, the existing process may in future be extended toward substrate fractionation, a biorefinery concept where value is added to all feedstock constituents.     

Field performance of transgenic sugarcane expressing isomaltulose synthase

Transgenic sugarcane plants expressing a vacuole‐targeted isomaltulose (IM) synthase in seven recipient genotypes (elite cultivars) were evaluated over 3 years at a field site typical of commercial cane growing conditions in the Burdekin district of Australia. IM concentration typically increased with internode maturity and comprised up to 217 mm (33% of total sugars) in whole‐cane juice. There was generally a comparable decrease in sucrose concentration, with no overall decrease in total sugars. Sugarcane is vegetatively propagated from stem cuttings known as setts. Culture‐derived plants were slower to establish and generally gave shorter and thinner stalks at harvest than those grown from field‐sourced setts in the initial field generations. However, after several cycles of field propagation, selections were obtained with cane yields similar to the recipient genotypes. There was no apparent adverse effect of IM accumulation on vigour assessed by stalk height and diameter or other visual indicators including germination of setts and establishment of stools. There was some inconsistency in IM levels in juice, between samplings of the vegetatively propagated transgenic lines. Until the causes are resolved, it is prudent to selectively propagate from stalks with higher IM levels in the initial vegetative field generations. Pol/Brix ratio allowed rapid identification of lines with high IM levels, using common sugar industry instruments. Sucrose isomerase activity was low in these transgenic lines, and the results indicate strong potential to develop sugarcane for commercial‐scale production of IM if higher activity can be engineered in appropriate developmental patterns.