植物生长延缓剂提高结缕草冬季抗寒性的初步研究

探讨了植物生长延缓剂对暖季型草坪草细叶结缕草冬季生长和抗寒性的影响，结果表明，适宜浓度的多效唑和烯效唑可延缓植株生长，提高叶绿素水平，增加叶片的可溶性糖和可溶性蛋白质含量，促进抗氧化酶活性，增强细胞的活性氧清除能力。降低质膜相对透性，从而有助于提高草坏草的抗寒能力。解决细叶结缕草冬季枯黄的问题。     

植物生长调节剂对草皮生产和草坪养护效果影响的研究

萘乙酸(NAA)、矮壮素(CCC)、多效唑(PP333)、生根粉(ABT)、脱落酸(ABA)、吲哚乙酸(IAA)影响销植草坪生根数、根长及新建草坪草株高、分蘖和叶片，研究结果表明：矮壮素、多效唑和脱落酸对降低株高、抑制叶片生长有较为明显的作用；脱落酸、萘乙酸、矮壮素和多效唑对野牛草、早熟禾和高羊茅分蘖均有显著的促进作用；萘乙酸、生根粉、吲哚乙酸和矮壮素对生根有一定的效果。在适宜浓度下，上述植物生长调节剂对快速成坪、减少徒长和修剪次数具有较好的效果。     

AM真菌与根瘤菌对紫花苜蓿镰刀菌萎蔫和根腐病的影响

通过温室盆栽试验,探究了丛枝菌根(arbuscular mycorrhizal,AM)真菌摩西管柄囊霉与苜蓿中华根瘤菌对紫花苜蓿尖孢镰刀菌萎蔫和根腐病的影响,以期为合理利用两类共生菌,提高苜蓿抗病性提供理论依据。试验共8个处理,分别为接种或不接种AM真菌、根瘤菌和病原菌以及两两组合。与对照相比,AM真菌降低紫花苜蓿萎蔫和根腐病发病率80.13%(P<0.05)。AM真菌和根瘤菌互作促进苜蓿养分吸收、叶绿素合成,互作处理较对照叶绿素含量(soil and plant analyzer development value,SPAD值)提高61.85%,茎叶N含量提高26.5倍、P含量提高54.3倍,紫花苜蓿茎叶干重提高23.4倍(P<0.05)。AM真菌促进了紫花苜蓿根瘤的形成,较对照根瘤数多111.73%;AM真菌与根瘤菌二者互作,进一步促进了紫花苜蓿生长、养分吸收,降低了紫花苜蓿发病率,同时显著影响紫花苜蓿根系相关生化指标。互作处理提高超氧化物歧化酶(superoxide dismutase,SOD)活性41.05%,β-1,3-葡聚糖酶(β-1,3-glucanase)活性33.9%,茉莉酸(jasmonic acid,JA)浓度23.32%,木质素(lignin)16.92%,脱落酸(abscisic acid,ABA)、一氧化氮(nitric oxide,NO)和过氧化氢(hydrogen peroxide,H 2O 2)浓度分别降低26.68%,9.63%和25.26%,丙二醛(malondialdehyde,MDA)含量降低24.57%。综上所述,摩西管柄囊霉与苜蓿中华根瘤菌互作,可有效减轻紫花苜蓿镰刀菌萎蔫和根腐病的发生,二者具有良好的生防潜力。     

菲和芘胁迫下AMF和PGPR对高羊茅生理生态的响应

旨在探究菲和芘胁迫下丛枝菌根真菌(AMF)与根围促生细菌(PGPR)对高羊茅生理生态的响应。以菲和芘1∶1混合处理浓度各0、50、100和150mg·kg^-1下对高羊茅接种AMF变形球囊霉(Gv)、PGPR荧光假单胞菌(Ps2-6)、Gv+Ps2-6和不接种对照共16个处理。结果表明,AMF、PGPR或AMF+PGPR处理均显著增加高羊茅生物量和菌根侵染率,增强植物光合作用,提高叶绿素含量,显著提高植物体内生理活性。在土壤中菲和芘100mg·kg^-1水平下,与对照相比,双接种Gv+Ps2-6处理的高羊茅叶片叶绿素a、b和总叶绿素含量分别提高57.7%、41.7%和51.8%;净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)和气孔导度(Gs)分别增加70.6%、100.0%、4.5%和78.6%;最大光化学效率(Fv/Fm)和PSⅡ潜在活性(Fv/Fo)分别提高2.2%和8.8%;超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性、可溶性糖和脯氨酸含量分别是对照的1.6、1.5、2.3和2.7倍,丙二醛含量比对照下降46.0%;高羊茅株高和地上鲜重分别比对照增加63.0%和69.6%;接种PGPR处理能够增加AMF侵染率以及菌根依赖性。供试条件下,双接种Gv+Ps2-6处理增加高羊茅叶绿素含量和抗氧化能力,增强光合作用能力,降低膜脂过氧化水平,促进植物生长的作用最为显著。     

植物生长调节剂对鸭茅种子产量的影响

植物生长调节剂已经广泛推广运用于牧草种子生产。以“滇北”鸭茅为试验材料,通过两年的大田试验探讨了不同浓度的矮壮素(500、750、1000、1250 g·hm^-2)和不同浓度抗倒酯(100、200、300、400 g·hm^-2)两种植物生长调节剂及其混合制剂(500+50、500+150、1000+50、1000+150 g·hm^-2)对鸭茅种子产量的影响。试验结果表明:喷施3种生长调节剂对鸭茅种子的产量均有提升,以混施矮壮素和抗倒酯(500+150 g·hm^-2)效果最佳,增产达46.2%。此外试验发现,生长调节剂主要是通过增加鸭茅种子田单位面积的生殖枝数目和结实率来提高鸭茅种子产量。喷施植物生长调节剂对千粒重及每穗小花数没有显著影响。     

Native and exotic seed dispersal by the stone marten (Martes foina): implications for the regeneration of a relict climactic forest in central Portugal

The stone marten (Martes foina) is a carnivorous mammal that often consumes fleshy fruits, thus potentially promoting seed dispersion. The present study was developed in Bussaco National Forest, central Portugal, and aimed to assess the potential role of the stone marten in dispersing native and exotic plants in different forest landscape types. Seeds from stone marten scats and fleshy fruits were collected monthly and were thereafter identified and sowed in a nursery, following a randomized experimental setup. Plant emergence was monitored fortnightly. Generalized linear models were used to test for differences in time and success of emergence between seeds from scats and fruits of 3 native species (Rubus ulmifolius, Arbutus unedo and Celtis australis) and 1 exotic plant species with invasive behavior (Prunus laurocerasus). Fruit consumption by the stone martens significantly increased and accelerated the germination of the native R. ulmifolius but had no effect on the other 2 native species or on the invasive species. This suggested that stone martens contribute to gene flow and forest regeneration by dispersing native plant seeds. However, although the germination was not enhanced in the invasive species, the preference of stone martens for these fruits may potentially contribute to the proliferation of P. laurocerasus. Our study represents a contribution to better understanding the fauna and flora interactions, enabling for a more conscious and effective decision‐making in forest management.     

景电灌区农田防护林衰败及优化模式

景电灌区农田防护林网是景电灌区防护林体系的重要组成部分,通过调查景电灌区农田防护林衰败现状,分析退化原因,提出优化改造模式,为景电灌区农田防护林更新改造从而发挥可持续效益提供技术支撑。结果表明,1)以杨树为主要树种的景电灌区农田防护林网目前呈严重衰败状态,尤其在个人管护的区域,残缺断代现象严重,部分地方甚至基本消失;2)病虫危害,耗水、胁地严重而被砍伐,耕地次生盐渍化导致树木生长不良、枯死,树种单一、结构不合理,管理不到位等是造成农田防护林衰败的主要原因;3)三倍体毛白杨(Populus tomentosa)、廊坊(P.langfanggensis)、樟子松(Pinus sylvestris)、刺槐(Robinia pseucdoacacia)、白蜡(Fraxinus chinensis)、鸣山大枣(Jujube minshan)等树种为该地区农田防护林建设的适宜树种,可采用农田防护林杨树优势树种轮换、针叶常绿树种优化改造、生态经济型防护林网营造等模式对景电灌区农田防护林网进行更新改造。农田防护林网的改造,将对完善防护林体系,保障景泰绿洲的安全产生重要意义。     

高羊茅雄性不育株花粉母细胞减数分裂染色体行为观察

采用卡宝品红染色制片法,对高羊茅(Festuca arundinacea)雄性不育植株花粉母细胞减数分裂过程及异常行为进行观察,结果发现,高羊茅减数分裂进程与小花大小、花药长度、色泽有较为密切的关系。减数分裂周期具有不同步性,同一制片中可观察到2～4个不同时期的分裂相,这种现象是高羊茅在进化过程中环境适应的一种表现,有利于增强种群繁殖稳定性。本研究还发现,减数分裂过程中存在大量单价体、染色体桥、落后染色体、不均等分离、微核、三分体等异常现象,初步分析确定这些小孢子异常分裂是导致高羊茅花粉败育的重要原因之一。     

石羊河上游退化草地植物功能群生态位分异特征——以阿尔泰狗哇花型草地为例

采用时空转换方式,以石羊河上游高山草地阿尔泰狗哇花Heteropappus altaicus型退化草地及其原生群落为研究对象,以其主要功能群结构特征调查为基础,研究各功能群生态位季节动态特征。结果表明：该区生态位季节动态变化趋势同功能群类别有关,与功能群所处的演替阶段无关;功能群生态位数量特征变化的绝对数量及相对数量受到其所处的演替阶段影响,表现为随季节的推移禾本科功能群生态位宽度上升,其上升相对值为退化样地（120.8%）高于原生群落（65.5%）;而杂类草下降,其下降相对值差异较小,依次为51.38%和66.34%。随季节的推移禾本科-杂类草生态位重叠度升高,且升高的幅度为退化样地(113.3%)略低于原生群落(119.4%),就升高的绝对值而言,原生群落各观测时期均低于退化草地;杂类草-禾本科生态位重叠度则逐渐降低,其相对数量在退化样地与原生群落中依次下降53.0%和54.9%。其中退化草地禾本科、杂类草生态位重叠度在7月中旬存在一个拐点,其前期禾本科-杂类草组对低于杂类草-禾本科组对,而后期刚好相反。造成上述现象的原因可能与功能群生长特性和放牧干扰共同作用有关。返青较早的禾本科功能群早期生长受到放牧干扰的影响,为返青较迟的杂类草生长提供较大的资源空间,从而使得杂类草功能群在“植被空隙中进行季节更新”,进而改变了原群落的功能群结构。阿尔泰狗哇花型退化草地是植物群落退化演替过程中的关键阶段,如果加以适当的管理,草原退化将得到一定程度的改善;如果不加以保护,草地继续退化后的不可预知风险将提高。     

Increase in plasma total antioxidant capacity of grazing Japanese Black heifers and cows in forestland in Japan

Blood total antioxidant capacity (TAC) has become a key bio‐marker for animal health. Forest‐grazing cattle are known to forage various native plants that have high TAC. This study evaluated differences of plasma TAC between forest‐grazing (FG) and pasture‐grazing cattle (PG). Experiment 1 monitored the plasma TAC levels of 32 Japanese Black cattle. The level in PG did not change throughout the grazing period. However, that in FG, which increased from summer, was significantly higher than that in PG through fall (P < 0.05). In experiment 2, we used nine Japanese Black heifers and investigated their blood antioxidant parameters and the TAC in plants that the cattle consumed in late June and September. The plasma TAC levels in FG were significantly higher than those in PG in both periods (P < 0.05). Plasma levels of lipid peroxidation in FG tended to be lower than that in PG (P = 0.098). Furthermore, the TAC levels in various species of shrubs and trees consumed by FG were higher than those in pasture grasses. Results of this study show that plasma TAC of grazing Japanese Black cattle in forestland increase from summer through fall.