波斯婆婆纳的无性繁殖

波斯婆婆纳(Veronica Persica Poir)是麦田恶性杂草之一。其特点是繁殖力强、生长速度快、生长期长、对麦苗危害性大、防除困难等。过去只注意其有性繁殖方式,而未重视以根、茎、叶营养器官无性繁殖方式。1989年9月笔者在麦田进行了无性繁殖试验。以新鲜的生长旺盛的波斯婆婆纳根、茎、叶为繁殖材料,按试验所需叶片数,切成不同茎段进行露头栽插和埋泥栽插。处理为:1.用2叶1心至5叶1心的茎段露头栽(地上留一段,地下     

睫毛婆婆纳

睫毛婆婆纳(Veronica hederaefoliaL inn.)又名常春藤叶婆婆纳,为玄参科婆婆纳属越年生或一年生草本植物。睫毛婆婆纳原产欧洲、西亚和北非等地中海沿岸国家,是当地极为重要的麦田杂草。上世纪80年代传入我国,在江苏南京和浙江定海有分布。本文在调查研究及查阅大量文献的基础上,归纳了外来杂草睫毛婆婆纳的形态特征、生活史、在我国的分布、可能扩散的区域、经济和生态影响、起源、引入路经、入侵途径、生境类型、营养和环境条件、预防、控制和管理措施等。     

低量化学除草剂对菌株QZ-97a侵染波斯婆婆纳的影响

为探索提高真菌除草剂防效的途径,研究了胶孢炭疽菌菌株QZ-97a与低剂量化学除草剂混用的互作效果。结果表明,菌株QZ-97a孢子悬浮液与低剂量的化学除草剂氯氟吡氧乙酸(Fluroxypyr,氯氟吡氧乙酸)混用可显著提高对波斯婆婆纳的防效。1.0×10~8个孢子/ml的菌株QZ-97a孢子悬浮液与常规剂量1/10的氯氟吡氧乙酸混用可在波斯婆婆纳危害时的田间条件下经保湿24～72h后使子叶期波斯婆婆纳死亡。可见,该菌与常用的防除波斯婆婆纳的化学除草剂配合性好,具有被开发为防除波斯婆婆纳的真菌除草剂的潜力。     

新外来杂草——常春藤叶婆婆纳

新外来杂草──常春藤叶婆婆纳郭水良，李扬汉（浙江师范大学生物系金华３２１００４）（南京农业大学农学系）常春藤叶婆婆纳（ＶｅｒｏｎｉａｈｅｄｅｒａｅｆｏｌｉａＬ．）原产欧洲、北非及西亚，是当地麦田的重要杂草。该杂草８０年代初传人我国，现在在江苏、浙江境...     

加拿大一枝黄花生物生态学特性及防治

本文归纳了外来杂草加拿大一枝黄花的形态特征、生活史、与近缘种的区别，在我国的分布、生境类型、营养和环境条件、可能扩散的区域、对经济和生态影响、起源、入侵途径、预防、控制和管理措施等。     

假高粱的特征特性及控制

假高粱又名石茅高粱、宿根高粱、阿拉伯高粱、约翰逊草、琼生草和亚刺伯高粱。学名Sorghum halepense(L．)Pers．[异名Holcus halepensis L．]，英文俗名Johnson grass，Aleppo Milletgrass。属单子叶植物纲(Monocotyledoneae)，莎草目(Cypera-les)，禾本科(Poaceae)，蜀黍属(Sorghum Moench)。     

11种除草剂对小麦田恶性杂草阿拉伯婆婆纳的防除效果

针对我国黄淮海冬麦部分区域恶性杂草阿拉伯婆婆纳,开展了田间茎叶处理除草剂筛选试验,并比较了不同施药时期防效的差异.结果表明,防除阿拉伯婆婆纳,越冬前施用除草剂的防效优于返青期施药,可选择10％苯磺隆可湿性粉剂27.00 g/hm2,或56％2甲4氯钠可溶粉剂1 260.00 g/hm2,或40％唑草酮水分散粒剂36.0...     

环吡氟草酮等6种除草剂对小麦田恶性杂草婆婆纳的活性

婆婆纳为小麦田重要恶性杂草,且防除难度较大。利用温室盆栽法评价环吡氟草酮等6种除草剂对婆婆纳的室内生物活性以及体内解毒代谢酶P450s的影响,以期为科学防除婆婆纳提供理论依据。盆栽药效试验结果表明,唑草酮、环吡氟草酮、啶磺草胺、2甲4氯钠对婆婆纳具有较高药效,在最低田间推荐剂量处理下,鲜重抑制率均高于90%;室内毒力测定结果表明,6种除草剂对婆婆纳的毒力高低为啶磺草胺>唑草酮>环吡氟草酮>氯氟吡氧乙酸>双唑草酮>2甲4氯钠。马拉硫磷预处理后,6种除草剂的增效作用明显,增效比值为1.76～2.62。表明唑草酮、环吡氟草酮、啶磺草胺对婆婆纳具有较高的生物活性,且P450s抑制剂马拉硫磷可提高6种除草剂对婆婆纳的活性。     

水葫芦[Eichhornia crassipes (Mart.) Solms.]

水葫芦又名凤眼莲 ;英文俗名为Waterhyacinth ;学名 :[Eichhorniacrassipes (Mart.)Solms .];属单子叶植物纲 (Monocotyledoneae) ,百合目 (Liliflorae) ,雨久花科 (Pontederiaceae)。1　形态特征水葫芦根状茎粗短 ,密生多数细长须根 ;叶基生 ,莲座式排列 ,叶片卵形、倒卵形至肾圆形 ,大小不一 ,宽约 4～ 12cm ,光滑 ,叶柄基部带紫红色、膨大呈葫芦状的气囊 ;有着紫色亮丽的花朵 ,最上面的花瓣上有一块兰色的扇型斑块 ,中央点缀着一个桃形鲜艳黄斑 ;绿叶杯状 ,叶茎基部膨大 ,使植株能够漂浮在水面 ;花茎单生 ,中部有鞘状苞片 ,穗状花序有…     

毒麦(Lolium temulentum L.)

毒麦学名：Lolium temulentum L．；英文俗名：Poison Ryegrass，Bearded Ryegrass，Darnel；属单子叶植物纲(Monocotyledoneae)莎草目(Cyperales)禾本科(Poaceae)黑麦草属(Lolium L．)。俗名黑麦子、迷糊、小尾巴麦子。     

Effects of phosphorus and light intensity on the growth and competition of the two weed species,Veronica persica and Chorispora tenella

Veronica persica Poir. (Persian speedwell) is an invasive alien weed species in the upland soils throughout China. Its dominance in weed flora could be alleviated by Chorispora tenella (Pall.) (tender chorispora) in P‐poor soils and in an intense light environment. Here, three experiments in growth chambers were carried out in order to explore the effect of P and light intensity on the growth and competition of V. persica and C. tenella, the pH value in their rhizospheres, and the kinetic parameters (K_m and V_max) of the H₂PO₄^‐ uptake by the two weed species. The ANOVA results showed that the light intensity and P level in the soil obviously influenced the growth of the two weed species. However, the effect of the P level in the soil was greater for V. persica and the effect of the light intensity was greater for C. tenella. The restriction of the growth of V. persica by a low P level in the soil was much more than that of C. tenella, but it was reversed in the two species in relation to a low light intensity. In addition, the pH was lower in the rhizosphere of C. tenella after the P‐deficient treatment and there was a lower K_m in the uptake of H₂PO₄^‐ than for V. persica, suggesting that C. tenella could adapt to a low‐P environment more easily. In conclusion, C. tenella growing together with V. persica had a competitive advantage under high‐light‐intensity and low‐P‐level conditions, but it lost its advantage with an increase in P fertilization and a decrease in light intensity.     

Seed dormancy and periodicity of seedling emergence in Veronica hederifolia L.

Emergence of Veronica hederifolia seedlings began in mid-October and continued into spring; few appeared from June to September. Ripe seeds shed in June were dormant but wben buried in soil outdoors developed a capacity for germination initially at low temperatures (constant4 C; daily alternations of 4-10° and 4-1 5 C) and later at somewhat higher temperatures, with peak germination in September-November. During winter, spring and early summer thc germination capacity declined, to increase again in late summer and early autumn. Cyclic physiological changes thus occur in seeds of V,hederifolia present in the soil, with which lhe consistent seasonal periodicity of seedling emergence is associated. In dry storage ihe capacity for germination progressively increased, but alter 12 months there was a sharp decline in germination at 4° C. Few seeds germinated at 20° C, but moistening with GA 4/7; brought about complete germination at this temperature.     

Weed interference and control in white yam (Dioscorea rotundata Poir)

The climbing growth habit of white yam (Dioscorea rotundata) coupled with its inability to shade the ground completely at any stage of its growth and development makes it very susceptible to weed interference. The critical period of weed interference in white yam was between the 8th and 16th week after planting (w.a.p.) for yam planted at the onset of rains. Keeping yam plants weedy for 16 w.a.p. or beyond significantly reduced tuber yield; keeping them weed-free for the same period resulted in a significant increase in tuber yield. A minimum of three weedings within 16 w.a.p. are necessary to minimize yield reduction caused by weeds. The lowest weed weight and highest crop yield from herbicide treatments were obtained where a mixture of fluometuron and metolachlor each at 2.0 kg a.i./ha was used for pre-emergence weed control.     

Detection and molecular characterization of a phytoplasma affecting Prunus persica L. in Jujuy, Argentina

Peach (Prunus persica L.) plants with symptoms of yellowing, reddening, curling and leaf necrosis, premature defoliation and internode shortening were observed in production fields in Jujuy province (Argentina). A phytoplasma was detected by PCR using the universal primer pairs P1/P7 and R16F2n/R16R2 in all the symptomatic samples analysed. The RFLP profile of PCR products, amplified with R16F2n/R16R2 primers, shows that this phytoplasma, named Argentinean Peach Yellows (ArPY), belongs to subgroup 16Sr III-B. The phylogenetic analysis of the 1244 bp 16S rDNA cloned sequence, grouped the ArPY phytoplasma into the X-disease group with a closer relationship with CFSD, PssWB and ChTDIII phytoplasmas. This is the first report of a phytoplasma infecting peach trees in Argentina.     

从系统角度分析克隆生长对婆婆纳属植物适应性的影响

克隆植物由于克隆性的存在,在很多方面同非克隆植物存在差异.为了解克隆生长对植物适应性的影响,以婆婆纳属(Veronica)植物为对象,从系统角度开展了其属内克隆植物与非克隆植物的比较研究.结果显示:①克隆性并不是一个保守性状,婆婆纳属的祖先状态中克隆植物可能性为0.94;②克隆植物大多为多年生植物,花部具有更大的吸引力,而非克隆植物中一年生植物占优势;③与克隆植物相比,非克隆植物更加耐干旱和高温.在婆婆纳属的进化过程中,随着气候日益变得干旱,利用种子的耐旱特性逃避恶劣时期的策略受到青睐,克隆生长的相对重要性逐渐降低,以致于一些植物最终转换成了非克隆植物,其对干旱环境的适应性更高,也能耐受更高的温度,从而能够适应当地环境的变化.     

Growth and competitiveness of Senecio madagascariensis Poir. (fireweed) in relation to fertilizer use and increases in soil fertility

The relative importance of increasing nutrient availability with regard to the growth and level of infestation of Senecio madagascariensis Poir. (fireweed) in pastures was assessed. In a ‘replacement series’ experiment with Avena strigosa Schreb. cv. Saia (oats), representing a vigorous annual competitor, total shoot dry weight of S. madagascariensis (when grown in pots alone or with oats) increased significantly (P<0.001) with increasing levels of nitrogen and phosphorus, but was unaffected by potassium levels. The relative growth of S. madagascariensis in mixtures of the two species, and hence the competitive advantage of the weed, generally increased at higher nitrogen and phosphorus levels. A greater percentage of dry matter was also partitioned into stems and flowering capitula, thereby raising its relative reproductive effort, and hence its invasive potential. Raising soil fertility through the use of nitrogen- or phosphorus-based fertilizers, or pasture legumes, is unliely in itself to suppress the growth of S. madagascariensis. Rather, fertilizer use may preferentially benefit the weed. Croissance et compétitivité de Senecio madagas-cariensis Pair, en relation avec la fertilisation et l'augmentation de la fertilité du sol L'importance relative de la disponibilité de nutriments croissants a été estimée sur la croissance et le taux d'infestation de Senecio madagascariensis dans les prairies. Dans une expérimentation de type ‘séries de remplacement’ avec Avena strigosa (Schreb) cv Saia (avoines), représentant un fort compétiteur annuel, le poids total de matière sèche de S. madagascariensis (cultivées en pots seuls ou avec avoines) a augmenté significativement (P< 0,001) avec une élévation des taux d'azote et de phosphore, mais n'a pas été affecté par le taux de potasse. La croissance relative de S. madagascariensis en mélange avec les deux espèces, et donc l'avantage dans la compétition de l'adventice, a en général augmenté avec des taux plus élevés en azote et phosphore. Un plus grand pourcentage de matière sèche était aussi réparti dans les tiges et les capitules foliaires, augmentant ainsi sa capacité reproductive et delà son potentiel d'envahissement. Augmenter la fertilité du sol à travers des engrais azotes et phosphores, ou des engrais verts est en soi-même non envisageable pour entraver la croissance de S. madagascariensis. L'utilisation d'engrais peut plutôt être profitable à l'adventice. Wachstum und Konkurrenzkraft von Senecio madagascariensis Poir. in Bezug auf Döngung und Zunahme der Bodenfruchtbarkeit Die Bedeutung steigender NährstoffVerfüg-barkeit für das Wachstum von Senecio madagascariensis und die Verunkrautung von Weideland mit dieser Pflanzenart wurde bestimmt. In einem Substitutionsversuch mit Sand-Hafer (Avena strigosa Schreb., ‘Saia’) als konkurrenzstarke einjährige Art nahmen die oberirdische Trockenmasse und damit der Konkurrenzvorteil von Senecio madagascariensis mit steigender Stickstoff- und Phosphorversorgung signifikant zu (P<0,001); Kalium blieb ohne Einfluß. Ein größerer Anteil der Trockenmasse wurde auch in die Stengel und die Blütenköpfchen, also die Reproduktion fördernd, eingelagert, wodurch das Invasionspotential wuchs. Durch Verbesserung der Bodenfruchtbarkeit durch Stickstoff-und Phosphordüngung oder Leguminosen kann das Wachstum von Senecio madagascariensis nicht unterdrückt werden. Düngung kommt in erster Linie dem Unkraut zugute.     

Effects of tropical weeds on yield in white yam (Dioscorea rotundata Poir)

The effects of tropical weeds on the yield of while yam were studied outdoors in wooden boxes. When the foliage and roots of weeds were in physical contact with the crop until harvest (full interference), tuber yield of yam was reduced by 76–79% of that obtained under weed-free conditions over 3 years of study. When there was no physical contact between roots of crop and weeds, the leachate from the weed zone caused tuber yield reductions of 42, 40 and 38% in 1978, 1979 and 1980, respectively, when it was applied to the yam zone. This leachate also reduced leaf area index (LAI) in the yam crop but the adverse effects on yam root and shoot biomass were less pronounced. This technique made it possible to separate competitive interference from allelopathic interference of tropical weeds with the yam crop.