Effects of Stable Chlorine Dioxide on Sterilization and Preservation of Fresh-cut Narrow-leaf Cattail

At present, chlorine dioxide has been widely used as a bactericide that may become an alternative to chlorine. In this study, fresh-cut narrow-leaf cattail was soaked with 45, 70 and 95 mg/L chlorine dioxide solution, respectively. Fresh-cut narrow-leaf cattail samples were collected regularly to determine changes in surface microbe amount, cellulose content, Vc content, reduction sugar content and sensory quality of narrow-leaf cattail, thus analyzing the effects of chlorine diox- ide on sterilization and preservation of fresh-cut narrow-leaf cattail. The results showed that all three concentrations of chlorine dioxide solution could significantly reduce the amount of microbes on the surface of fresh-cut narrow-leaf cattail and improve the edible safety of products. The initial sterilization efficiency was im- proved gradually as the concentration of chlorine dioxide increased. In addition, chlorine dioxide treatment postponed the increase of cellulose content of fresh-cut narrow-leaf cattail. However, chlorine dioxide oxidized Vc and reducing sugar, and its bleaching effect also exerted a certain impact on the sensory quality of fresh- cut narrow-leaf cattail. Based on comprehensive comparisons, 45 - 70 mg/L chlorine dioxide solution exerted the best effects on sterilization and preservation of fresh-cut narrow-leaf cattail. This study laid the foundation for the production and application of chlorine dioxide solution and promotion of rapid development of nar- row-leaf cattail industry.

The Biology of <i>Szelenyiopria talitae</i>(Hymenoptera: Diapriidae): Larval Parasitoid of the Leaf-Cutting Ant <i>Acromyrmex subterraneus</i>(Hymenoptera: Formicidae)

The biology of a koinobiont parasitoid of leaf-cutting ant larvae, Szelenyiopria talitae (Hymenoptera: Diapriidae), was studied from naturally infested Acromyrmex subterraneus (Hymenoptera: Formicidae) nests. Nests were collected in the field from the Atlantic rainforest biome in the state of Rio de Janeiro. A total of fifty-three nests were collected from 2015 to 2018. Parasitized nests were only found during the months of September and October. Approximately 22% of the nests collected over a four-year period were found to have been parasitized by S. talitae. The mean within-nest parasitism rate was 66.3%. This diapriid displayed both solitary (14%) and gregarious parasitism (86%), with up to a maximum of 12 parasitoids developing within a single host. Gregarious parasitism with two (29%) or three (21%) S. talitae per host was most frequently observed. There was a positive correlation between the number of parasitoids per host and host size (dry weight), indicating that S. talitae females oviposited a higher number of eggs in larger hosts. There was also a negative correlation between S. talitae pharate adult size and the number of parasitoids per host, which could have been caused by sibling competition for limited host resources. The high levels of parasitism seen here had a debilitating effect on the colonies. Acromyrmex subterraneus is a serious pest in Brazil, and these studies lay the foundation for understanding the impact of S. talitae on ant populations.

Attractivity or Repellence: Relation between the Endophytic Fungi of <i>Acalypha</i>, <i>Colocasia</i>and the Leaf-Cutting Ants—<i>Atta sexdens</i>

Symbiotic relations are present in the nature and can contribute to the success of the organisms involved. Endophytic fungi live within the leaf tissues without causing any harm to the host plant, and some of them can be a defense mechanism against the attack by the leaf-cutting ants. Ants of the genus Atta are known as leaf-cutting ants and have an obligatory association with the fungus Leucoagaricus gongylophorus, cutting pieces of leaves and bringing them back to the colony to the fungus. The present study aimed to find out the endophytic fungi community of an attractive plant (Acalypha wilkesiana) and a less attractive plant (Colocasia esculenta) to the ants Atta sexdens. We found out that the communities are different in quantity and in composition and 73% of the isolated fungi were from A. wilkesiana, which has fungi known as attractive to leaf-cutting ants, such as genus Colletotrichum, Pestalotiopsis, Phomopsis and Xylaria. On the other hand, in C. esculenta, there was found the genus Fusarium, known to be reject by the leaf-cutting ants, and less fungal diversity than in the attractive plant A. wilkesiana. Therefore, our data suggest that attractivity or repelence of a plant to the leaf-cutting ants could be related to presence or ausence of determinated fungi more than the quantity of fungi present in a leaf.

Spatial Statistics and Age Structure of Leaf Cutting Ant Nests

In this study, we investigated the spatial aggregation of old and incipient nests of Atta sexdens rubropilosa by fitting Poisson and Negative binomial models to nest abundance data. Our aim is to analyse the distribution of ant nests in eucalypt regrowth, Cerrado and native forest fragment. We also investigated the correlation between nest abundance and climatic factors, as well as different nest ages. When comparing nests of different ages we observed an aggregated pattern for both old and incipient nests. On the other hand, analysing the distribution of nests separately, only taking into account the different areas and respective borders, old nests exhibited an aggregated pattern and incipient nests showed a random pattern, except for native forest with ants exhibiting only an aggregated pattern. The levels of aggregation changed in response to different areas and border gradients, with more external borders showing higher aggregation than more internal borders. Temperature was the variable showing the highest correlation with nest abundance and the correlation between nests of different ages was totally depending on the different areas.

Effect of Leafy and Leafless Greenwood, Softwood and Hardwood Cuttings Success of <i>Garcinia kola</i>(Heckel)

Garcinia kola Heckel, called “petit cola” in Côte d’Ivoire and “bitter kola” in Nigeria, is a Non-Timber Forest Product of great socioeconomic importance. Unfortunately, this species is threatened due to overexploitation and deforestation. This study tested the effect of leaf area on stem cuttings to regenerate vegetatively in a non-mist poly-propagator without using exogenous hormones. Three stem cuttings types: greenwood, softwood and hardwood (12 - 15 cm in length) were collected from 24-month years old seedlings. The two top leaves of each cutting type were conserved at different leaf area: 0 cm2, 28.25 cm2, 56.5 cm2, 84.75 cm2 and 113 cm2 (entire leaf area). Observations were made on rooting, sprouting and leafing abilities of cuttings depending to treatments applied. Results showed that all cutting types have presented good ability to shooting and rooting. Cuttings with 113 cm2 leaf areas presented the best rooting (94.44% ± 2.42%) and shouting (95.55% ± 2.42%) percentage and longest primary root length (12.03 ± 0.50 cm). Hardwood, softwood and greenwood cuttings with 113 cm2 leaf area had the best rooting percentage (96.66% ± 3.33%, 96.66% ± 5.77% and 90.00% ± 5.77% respectively). The longest primary root length (13.50 ± 0.97 cm) was observed to greenwood cuttings with 113 cm2 leaf area. Regenerated plants in the forest presented well survival percentage (96.66%). This study shows that it is possible to regenerate entire plants by cuttings without using external hormones in non-mist poly-propagator.

Effect of Synthetic Hormone Substitutes on Rooting of Vine Cuttings in Water Yam (Dioscorea alata L.)

The use of yam vine cuttings as propagules with appropriate synthetic rooting hormones such as IBA (Indole-Butyric Acid) and NAA (Naphthalene Acetic Acid) has previously been reported as successful but expensive. To source for cheaper alternatives, this study compared the effect of some natural and synthetic hormones on rooting of vine cuttings in two varieties of Dioscorea alata. Vine cuttings from three months old water yam varieties were treated separately with 1%, 3% and 5% concentrations of each of the following: neem leaf ash, coconut water, 2,4-D and IBA with water as control. Treated cuttings were planted in triplicates in polythene bags using the completely randomised design and watered once in two days for 49 days. Data collected on rooting percentage, number of roots per plant, mean root length, number and length of new vines were subjected to analysis of variance tests and the means separated using least significant difference tests. A 100% rooting was observed in vines treated with 1% or 3% coconut water and neem ash. These vines also generated significantly greater number of new vines (P < 0.05) compared to those from synthetic hormones. Vines treated with 5% neem produced the highest number of roots (145.33 ± 9.21;P < 0.001) while those treated with 3% neem produced the longest roots (45.3 ± 9.23 cm) followed by those treated with 3% coconut water (24.3 ± 3.48). The study reveals that neem leaf ash and coconut water are better root promoting agents for water yam vines than 2,4-D and IBA and could be tested further for use as natural hormonal substitutes to the synthetic hormones.

小蚕饲育切桑机结构设计与性能分析

针对小蚕饲养过程中桑叶切割效率低下问题,文中设计了一种集自动切割、自动清理等功能于一体的自动切桑机。文中采用Solid Works建立了切桑机的模型,介绍了传动系统、切割机构和清理机构等主要结构的设计,并从桑叶切割大小、桑叶切割质量和桑叶切割效率3个方面对切桑机的性能进行分析,提出了一种通过控制刀具转速切割不同规格大小桑叶的方法,得出了切割1 cm×2 cm,1.5 cm×2 cm和2 cm×2 cm三种规格大小的桑叶所需的刀具转速、相对速度和切割效率,最高切割效率可达624 kg∕h。

不同剪梢程度对农桑14号春季经济性状及产叶量构成的影响

[目的]分析不同剪梢程度对农桑14号春季经济性状和桑叶产量及其构成的影响,为农桑14号的春季剪梢提供技术参考。[方法]对桑树枝条进行1/4、1/3、1/2剪梢处理,调查不同处理的发育历期、止芯芽性状、生长芽性状、枝条长度及桑叶产量表现。[结果]在发育时间上,剪梢1/4、1/3与剪梢1/2的处理从膨芽期到雀口期,发育历期呈增大趋势;在开叶阶段,发育历期呈缩短趋势;到桑叶成熟期,发育历期呈增大趋势。在桑叶产量及其构成上,剪梢1/4处理平均产量2.413 kg/株,其中生长芽叶重2.068 kg/株,占85.70%,止芯芽叶重0.345 kg/株,占14.30%;剪梢1/3处理平均产量3.042 kg/株,其中生长芽叶重2.612 kg/株,占85.86%,止芯芽叶重0.345 kg/株,占11.34%;剪梢1/2处理平均产量2.172 kg/株,其中生长芽叶重1.875 kg/株,占86.33%,止芯芽叶重0.297 kg/株,占13.67%。[结论]采用1/4或1/3剪梢处理,大蚕用叶可提前到4月28日,且桑叶产量高于1/2剪梢处理,对全年多批次养蚕的时间调控和桑叶保障更加有利。

莓叶委陵菜叶插繁殖技术研究

莓叶委陵菜(Potentilla fragarioidis)作为我国北方地区极具开发潜力的乡土地被植物,存在着有性繁殖材料不易获得且繁殖系数较低的问题。而扦插繁殖作为一种无性繁殖手段,能为莓叶委陵菜的快速繁殖提供新的途径。本研究以莓叶委陵菜生长健壮、无病虫害的叶为试验材料,通过正交试验针对不同扦插基质、激素种类及其浓度对莓叶委陵菜叶插生根效果的影响进行探究。结果表明,莓叶委陵菜插穗在扦插45 d后能够形成根系,不同处理水平的扦插基质、激素种类及其浓度间的交互效应对插穗生根效果的影响具有显著差异(P<0.05)。扦插基质是影响莓叶委陵菜叶插生根率的主导因子,而激素种类是影响平均单株生根数、平均单株总根长、最长根长和根系效果指数的主要因素。以草炭+珍珠岩+蛭石(1:1:1)为基质,扦插前使用300 mg·L^(-1)的IBA对插穗进行处理生根效果最佳,该处理方式下扦插生根率达63.33%,平均单株生根数为6.90条,平均单株总根长为27.98 cm,最长根长13.83 cm,根系效果指数达20.50。本研究结果可为莓叶委陵菜无性系繁殖体系的快速建立提供理论依据。

黑果腺肋花楸扦插生根特性及不定根发生模式研究

【目的】为了解黑果腺肋花楸扦插不定根起源及发育过程,揭示其扦插生根机理。【方法】以‘福康源1号’当年生半木质化插穗为研究材料,利用水培扦插技术和石蜡切片法对不定根形成过程中插穗内部组织结构及外部形态的变化规律进行观察。【结果】在水培条件下,IBA处理扦插生根期为30~40 d,扦插过程中皮孔处在10~15 d出现不定根,插穗切口处在15~20 d出现不定根,生根速度、不定根数量及根长均优于对照,外源诱导可显著提高生根率和生根质量。扦插前的插穗内无潜伏根原基存在,不定根原基在插后形成;不定根形成为愈伤组织生根型和内部分生组织生根型。皮部产生的不定根起源于维管形成层、韧皮薄壁细胞或皮层;愈伤组织产生的不定根是由愈伤组织内的薄壁细胞团特化而成;叶隙或枝隙是形成不定根原基和产生愈伤组织的主要区域。【结论】扦插生根属于多位点发生模式,属于诱导生根型。

4TQ-2A型甜菜切顶机的设计与试验

针对现有分段式甜菜切顶机切顶效率低、效果差等问题,设计了4TQ-2A型甜菜切顶机,采用两回转轴对向旋转方式清理缨叶,并通过单因素试验确定了橡胶条型号和最佳工作转速。同时,通过对切顶装置结构及其在工作过程中运动特性分析,确定了切顶装置的关键尺寸和最佳切割角度。田间试验表明:4TQ-2A型甜菜切顶机设计合理,当前进速度为1m/s、清缨装置转速为800r/min、切顶装置切割角为30°时,经过5次重复试验得到切顶合格率平均值为95.56%,甜菜损伤率平均值为2.6%,有效解决了甜菜缨叶清理不净、切刀易堵塞等问题,降低了作业过程中甜菜的损伤率,提高了切顶质量及合格率,满足甜菜机械化切顶作业要求。研究可为甜菜机械化收获装备的进一步研究奠定基础。

三七茎叶采收机仿生切割刀片设计与试验

针对传统三七茎叶采收机切割刀片在滑切减阻、刀片刃口锋利性等方面存在明显不足,以切叶蚁上颚结构特征为仿生原型,运用逆向工程技术,提取切叶蚁上颚轮廓曲线,分别基于切叶蚁的切齿齿顶尖锐端和上颚轮廓曲线设计了A、B两种不同的仿生切割刀片;开展了EDEM仿真与台架对比试验,仿真试验结果表明,仿生刀片A、B相较于传统刀片的平均最大剪切力分别降低7.74%和3.07%;台架试验结果表明,仿生刀片A、B相较于传统刀片的平均最大剪切力分别降低8.84%和2.53%,并且仿生刀片A、B在提高三七茎秆横切面平整度方面效果显著;3种刀片仿真试验与台架试验所测得的最大剪切力误差均不大于3.64%,仿真试验结果与实际试验结果基本一致。以刀型、切割倾角、切割速度为试验因素,开展正交试验,确定了较优参数组合为仿生刀片A、切割倾角0°、切割速度400 mm/min。基于较优参数组合开展田间试验,结果显示其对三七茎叶采收平均完整率为97.37%,较传统刀片提升2.01个百分点,平均漏割率为2.64%,较传统刀片降低1.46个百分点,表明以切叶蚁上颚切齿齿顶尖锐端为特征点设计的仿生刀片能够有效提升三七采收机作业性能。

非遗文化黄梅挑花对地方特产的包装设计研究——以黄梅荷叶茶为例

黄梅挑花作为湖北省黄梅县非物质文化遗产,具有独特的地域特征和艺术价值。黄梅荷叶茶历史悠久,是黄梅县当地的特色产品。本文对黄梅挑花装饰艺术进行分析,将黄梅挑花的艺术形式运用到黄梅荷叶茶的包装设计中,旨在探索出一条将非遗文化与地方特产相结合的包装设计方法,为助力乡村振兴和弘扬非物质文化寻求新的路径。

激素和插穗处理对乌饭树扦插生根的影响

以乌饭树当年生嫩枝为材料,对影响插穗生根的枝条部位、叶片面积和激素等因子进行了系统的研究。结果表明:枝条部位对乌饭树插穗生根率无显著影响,但以用枝条中、上部作插穗时,扦插后根系生长情况显著优于基部。一定量的叶面积可以促进乌饭树扦插生根,试验中插穗保留1片叶处理扦插效果较好。运用L9(34)正交试验对影响插穗扦插生根的激素相关因子进行分析,得出对生根率影响的主次顺序为激素种类>处理时间>质量浓度,各因素的最佳处理水平分别是:激素种类为NAA或IBA,激素质量浓度为1 000 mg·L-1,浸泡时间为1 min。综上所述,选择带有1片叶的中、上部枝条作为插穗,用质量浓度为1 000 mg·L-1NAA或IBA处理插穗1 min,此时乌饭树扦插的生根效果最好。

源库比改变对玉米生育后期茎鞘贮存物质含量及产量的影响

通过对吐丝授粉期两种密度条件下的两个不同类型玉米品种剪1/2叶、剪1/2穗和断1/2根的研究发现:剪叶、断根减源后植株体内可溶性糖浓度下降2.19%～38.6%,剪穗缩库后可溶性糖浓度上升23.17%～38.5%,而单株生产力降低4.1%～40.94%.试验表明:玉米产量的形成与源库关系的协调性有关.

插穗类型和留叶量对莲雾扦插生根及光合参数的影响

在种苗智能化快繁系统调控下,比较3种枝梢类型插穗及其不同留叶量处理对扦插成活率、生根性状、叶绿素含量及叶绿素荧光参数的影响。结果表明,3种枝梢类型中,绿色枝成活率最高,褐色枝成活率最低;在生根量、根条数、根长、根粗等生根性状上,绿色枝与绿褐枝插穗之间差异较小,与褐色枝之间差异较大;留叶量对插穗生根及成活率存在明显影响,无叶处理的插穗成活率为零,留2/4、3/4片叶处理的插穗成活率、根系性状均优于留全叶片处理;绿色枝插穗、绿褐枝插穗的不同留叶量处理间叶绿素含量、叶绿素荧光Y值差异不显著,而褐色枝插穗以留2/4片叶处理的叶绿素含量、叶绿素荧光Y值最大。研究表明,莲雾扦插以绿色枝插穗、绿褐枝插穗为佳,插穗留叶量以留2/4片叶或留3/4片叶为宜。

4种报春苣苔属植物叶插繁殖技术研究

以河池报春苣苔（Primulinahochiensis）、线叶报春苣苔（Plinearifolia）、永福报春苣苔（P、yungfuensis）、尖萼报春苣苔（Ppungentisepala）为研究对象，采用多因素完全随机区组试验设计，探讨3种扦插方式和3种扦插基质对4种报春苣苔属植物扦插生根的影响。结果表明，4种报春苣苔属植物在珍珠岩：草炭=1：1（V／V）基质中的扦插效果最好，形成的子株数最多（19．67-29．67），不定根发生时间最短（28．33．41d），不定芽发生时间最快（63．67-79．67d）；河池报春苣苔以全叶插方式繁殖效果最好，线叶报春苣苔、永福报春苣苔、尖萼报春苣苔以半叶插方式繁殖效果最好。

烤烟梗丝与叶丝卷烟主流烟气香味成分的差异性分析

对烤烟梗丝与叶丝卷烟主流烟气香味成分进行比对分析,为梗丝在卷烟配方设计和减害降焦中的应用提供理论参考。选取国内主产区云南曲靖的烤烟烟梗及其对应片烟,对其制丝后的94种卷烟主流烟气香味成分进行差异性分析,结果表明:以单支卷烟计,梗丝卷烟主流烟气中22种碱性成分总量约为叶丝烟气的1/5,除2,6-二甲基吡嗪外,其余21种碱性成分均低于叶丝卷烟;梗丝卷烟主流烟气中47种中性成分总量约为叶丝烟气的1/2,释放量低于叶丝卷烟的中性成分有42种;梗丝卷烟主流烟气中25种酸性成分总量约为叶丝烟气的1/20,各具体成分的释放量也均低于叶丝卷烟。以单位焦油计,梗丝卷烟主流烟气碱性香味成分的释放总量约为叶丝卷烟的1/2,其中明显低于叶丝卷烟的碱性成分有14种;梗丝卷烟主流烟气中性香味成分的释放总量与叶丝卷烟基本相当,其中明显低于叶丝卷烟的中性成分有34种;梗丝卷烟主流烟气酸性香味成分的释放总量为叶丝卷烟的1/7,除戊酸外,其余24种酸性香味成分的释放量均明显低于叶丝卷烟。梗丝烟气香味成分与叶丝烟气香味成分的种类组成基本一致,但梗丝烟气与叶丝烟气各具体香味成分的含量存在很大差异;采用梗丝掺配技术在降低卷烟焦油的同时,应有针对性地利用补香、增香技术来减少卷烟烟气香味成分的损失。

伤根·留叶数·采收方式对K326上部叶烟碱及生理性状的影响

以伤根、留叶数、上部叶不同采收方式3因素组合按L9(34)正交试验研究了K326上部叶烟碱含量及某些生理性状的变化。结果表明:各处理上部叶烟碱含量与对照相比总体上呈下降趋势。伤根面对上部叶烟碱含量的影响最大,达极显著水平;留叶数和不同采收方式对上部叶烟碱含量的影响达显著水平。各处理烟株上部叶的净光合速率、蒸腾速率和硝酸还原酶活性总体呈下降趋势;在3面伤根的影响下,上部叶气孔导度显著降低,而12、面伤根的影响无明显规律。

5种报春苣苔属植物的叶插繁殖研究

研究6种基质、3种IBA浓度处理和5种叶片切割方式对5种报春苣苔属植物叶插成活的影响。结果表明:基质、IBA浓度及切割方式对5种报春苣苔的叶片扦插具有明显的影响;其中泥炭混河沙(体积比1∶1)、泥炭混珍珠岩(体积比1∶1)是5种报春苣苔更适宜的叶插基质;除柳江报春苣苔外,3种IBA浓度处理对其他4种报春苣苔的叶插成活率无显著影响,但200 mg/L处理插穗的子株数和子株叶片数最多;叶片不同切割方式对不同报春苣苔的叶插效果不同,褐纹报春苣苔以全切的方式为宜,癞叶报春苣苔和石蝴蝶状报春苣苔以不切的方式为宜,柳江报春苣苔以不切、纵切、横切(叶尖朝上)和全切的方式皆可,大根报春苣苔以全切和纵切为宜。