Plant growth inhibitors in turmeric (Curcuma longa) and their effects on Bidens pilosa

Turmeric (Curcuma spp.) has numerous biological activities, including anticancer, antibacterial, antifungal and insecticidal properties. Here, we evaluated the plant growth‐inhibitory activities of two cultivars of Curcuma longa (C. longa ; Ryudai gold and Okinawa ukon) against radish, cress, lettuce and Bidens pilosa (B. pilosa ). The methanol extracts of both turmeric varieties inhibited the seed germination and seedling growth of all the tested plants. Ryudai gold had a significantly higher inhibitory effect on the seed germination and root and shoot growth of the plants than Okinawa ukon. Therefore, Ryudai gold was chosen for the isolation of plant growth‐inhibitory compounds using a silica gel column and high‐performance liquid chromatography. The structural identification of the compounds was carried out using ¹H NMR, ¹³C NMR and liquid chromatography–tandem mass spectrometry. The growth inhibitors were identified as four curcuminoids; dihydrobisdemethoxycurcumin ( 1 ), bisdemethoxycurcumin ( 2 ), demethoxycurcumin ( 3 ) and curcumin ( 4 ). The IC₅₀ of the curcuminoids against the root and shoot growth of B. pilosa ranged from 8.7 ± 1.7 to 12.9 ± 1.8 and from 15.5 ± 1.8 to 38.9 ± 2.8 μmol L^?1, respectively. Compound 1 showed the lowest IC₅₀ against the root and shoot growth of B. pilosa . These results suggested that Ryudai gold has a potential growth‐inhibitory effect against B. pilosa .     

Agronomic practises for weed control in turmeric (Curcuma longa L.)

Weeds are the main problem with turmeric (Curcuma longa L.) cultivation where herbicides are not allowed. This is because herbicides cause water contamination, air pollution, soil microorganism hazards, health hazards, and food risks. Considering turmeric's medicinal value and the environmental problems caused by herbicides, various agronomic practises have been evaluated for non‐chemical weed control in turmeric. One additional weeding is required before turmeric emergence and weed infestation is much higher when turmeric is planted in February and March, as compared to April, May or June planting. A similarly higher yield of turmeric is achieved when it is planted in February, March, and April, compared to late plantings. Weed emergence and interference are not affected by planting depth, seed size, planting pattern, planting space, ridge spacing, and the row number of turmeric until 60 days after planting. This is because turmeric cannot develop a canopy structure until then. Thereafter, weed infestation reduces similarly and significantly when turmeric is planted at depths of 8, 12, and 16 cm, compared to shallower depths. The yield of turmeric at these depths is statistically the same, but the yield for the 16 cm depth is difficult to harvest and it tends to decrease. Turmeric grown from seed rhizomes (daughter rhizomes) weighing 30–40 g reduces weed infestation significantly and obtains a significantly higher yield compared to smaller seeds. The mother rhizome also can suppress weed infestation and increase the yield markedly. Around 9% weed control and 11% higher yield are achieved by planting turmeric in a triangular pattern compared to a quadrate pattern. The lowest weed infestation is found in turmeric grown in a 20 or 30 cm triangular pattern and the highest yield is obtained with the 30 cm triangular pattern. Turmeric gown on two‐row ridges spaced 75 cm apart shows excellent weed control efficiency and obtains the highest yield. This review concludes that turmeric seed rhizomes of 30–40 g and/or the mother rhizome could be planted in a 30 cm triangular pattern at the depth of 8–12 cm on two‐row ridges spaced 75–100 cm apart during March to April in order to reduce weed interference and obtain a higher yield. Mulching also suppresses weed growth and improves the yield. The above agronomic practises could not control weeds completely; biological weed management practises could be integrated in turmeric fields using rabbits, goats, sheep, ducks, cover crops or intercrops.     

Biology of rhizome fly,Mimegralla coeruleifrons Macquart (Micropezidae: Diptera) in India,a pest of turmeric and ginger crops

Abstract

The observations were made on the life history of rhizome fly, Mimegralla coeruleifrons Macquart on turmeric and ginger plants. A female laid from 76 to 150 eggs in the soil under laboratory conditions. The incubation period varied from 2 to 5 days. Three larval instars were observed. The durations of first, second and third instars were 4 to 7, 4 to 8 and 3 to 10 days, respectively. The total larval period ranged from 13 to 25 days. The pupal period lasted for 5 to 15 days, adults from 7 to 24 days, and the total life span from 38 to 62 days. The sex ratio was 1: 1 approximately. The stages are described. A parasite, Trichopria sp was recorded from its pupae. The pupal stage appeared to be responsible for carry over of the pest in planting seed rhizomes from season to another. The peak period of infestation in endemic areas was from mid August to mid October.     

Identification of resistance to Pratylenchus thornei,P. neglectus,P. penetrans and Ditylenchus dipsaci in Turkish accessions of five wild chickpea species (Cicer bijugum,C. echinospermum,C. pinnatifidum,C. reticulatum and C. turcicum)

Phytoparasitica - Plant-parasitic nematodes feed and reproduce in chickpea roots. Root-lesion nematodes are one of the most important biotic factors to limit chickpea production in the world. The...     

Investigation of the host ranges of the leaf blotch pathogens of onion (Cladosporium allii-cepae) and leek (C. allii)

Inoculation of a range of Allium species and two non-alliaceous species with isolates of Cladosporiumallii-cepae and C. allii , obtained from onion and leek, respectively, demonstrated that the two pathogens had distinct host ranges. Conidia of C. allii-cepae, applied either dry or in aqueous suspension, infected A. altaicum, A. fistulosum (Japanese bunching onion), A. cepa (bulb onion), A. cepa var. ascalonicum (shallot), A. galanthum, A. pskemense and A. vavilovii . Dry conidia of C. allii applied at a high concentration caused atypical necrosis on A. altaicum, A. fistulosum, A. cepa var. ascalonicum, A. galanthum, A. pskemense, A. vavilovii, A. sativum (garlic), A. ampeloprasum and A. porrum (leek). Only A. ampeloprasum and A. porrum became typically infected following inoculation with conidia applied dry at low concentration or in aqueous suspension. Isolates of C. allii from leek failed to infect A. vineale, the type host. The length of conidia of a single isolate of C. allii-cepae varied significantly on different Allium spp.     

Trapping Cryptophlebia illepida and C. ombrodelta (Lepidoptera: Tortricidae) in macadamia in Hawaii

Abstract

Two species of Cryptophlebia found in Hawaii's macadamia orchards are active in different parts of a tree canopy. C. illepida (Butler) males were mostly caught in traps hung 1·5 m to 9.1 m from the ground; whereas C. ombrodelta (Lower) males were caught from 9.1 m to 15.2 m. A plastic, cylindrical sticky trap caught equal numbers of C. illepida males as Pherocon 1C traps but more than delta traps. A synthetic pheromone blend of 93% (Z)‐8‐dodecenyl acetate, 4% (E)‐8‐dodecenyl acetate, 1% (Z)‐8‐dodecenol, and 2% (2)‐7‐dedecenyl acetate attracted more males than other blends. No significant differences were detected between the two Cryptophlebia species in their response to the four‐component pheromone blend when traps were hung 4.6 m from the ground.     

树木年轮~(13)C/~(12)C比率记录的树木生长与生态环境关系的研究

树木年轮1 3C/1 2 C对气候的响应是一个复杂的过程 ,气候影响树木的光合作用、呼吸作用等生理过程 ,进而影响树木代谢物质的生成和流动及其同位素的分馏。对树木生长和树轮稳定碳同位素含量与生态环境之间关系的响应的全面分析研究 ,可以更为准确的获得树木年轮同位素1 3C/1 2 C比率与历史气候环境变迁关系的资料。本文在总结前人研究结果的基础上 ,得出以下几点结论 :1 .生态环境决定树木叶片的气孔导通度 ,而导通度又影响植物同化速率 ,进而影响树轮中稳定碳同位素的比率 ;2 .大气CO2 的浓度影响植物对水分的利用效率 ,而植物对水分的利用直接影响树木光合作用的速率 ,进而植物碳同位素比率记录了环境CO2的浓度的变化规律 ;3.植物同化速率和气孔导度与气候要素 ,如温度、湿度、降水、光照及风等气候要素有关 ;4.树木年轮1 3C/1 2 C比率与生态环境的响应的众多研究结果表明稳定碳同位素同环境的相关既存在空间差异也存在树种差异。     

姜黄对朱砂叶螨的生物活性

系统研究了姜黄Curcuma longa的正己烷、苯、无水乙醚、甲醇和水等溶剂的顺序和平行提取物对朱砂叶螨的生物活性.测定不同提取物对朱砂叶螨的触杀毒力.结果表明:处理72h姜黄的顺序提取物中,正己烷和苯提取物对朱砂叶螨的校正死亡率均为100%;在平行提取中,72h正己烷、苯、无水乙醚、甲醇和水提取物对该螨的LC50分别为0.7753、0.0993、0.9855、0.7873和0.8384 g·L-1.     

我国梭梭林地理分布和适应环境及种源变异

提要:综合国内对梭梭的研究成果,阐述了我国梭梭林的地理分布、群落特征、林分结构、适生环境、种源变异,并提出了今后的研究方向和保护策略,为梭梭的推广应用和生产经营提供借鉴。     

星豹蛛在丘陵山地的活动规律初步研究

用陷阱法和目测法对丘陵区各个栖境的星豹蛛Pardosa astrigera C．L．Koch(Ly- cosidae：Pardosa C．L．Koch)做了初步调查研究,结果表明,星豹蛛5月下旬前主要在边界、沟渠、碎石路和斜坡处活动,而苹果园中相对较少。当边界、沟渠和碎石路植被长高后,星豹蛛迁移至周围的苹果园中。6月下旬7月下旬苹果园中星豹蛛受高温影响数量下降明显；8月下9月其数量又有较大回升。研究还发现,10月中下旬星豹蛛在背阴地带出现的频率明显少于光照较好的地带；同期星豹蛛可能还有趋向干枯杂草的习性。     

梭梭幼苗根系分泌物提取方法的研究

为了探讨梭梭根系分泌物中的化学成分,本文采用水浸提取和循环灌溉两种方法对梭梭幼苗根系分泌物进行收集和提取,结合气相色谱-质谱联用分析技术,分析梭梭幼苗根系分泌物中组分和含量的差异。实验结果表明:循环灌溉收集的梭梭幼苗根系分泌物中检测到35种化合物,包括酚醌类、醛酮类、醇类、酸类、脂类和胺类化合物;硅烷化处理后,主要增加部分强极性有机酸,如苯甲酸。水浸提取梭梭幼苗根系分泌物的中性相组分共检测出27种化合物,但未检测到酚醌类化合物;碱性相组分共检测出23种化合物,醛酮类化合物种类减少,烷烃类化合物种类增加;酸性相组分中仅检测到10种化合物,以醇类化合物为主,占检出化合物总量的72.62%。收集梭梭幼苗根系分泌物循环灌溉是一种有效的方法。     

Growth of Trachipleistophora hominis (Microsporidia: Pleistophoridae) in C2,C12 mouse myoblast cells and response to treatment with albendazole.

The microsporidium Trachipleistophora hominis Hollister, Canning, Weidner, Field, Kench et Marriott, 1996, originally isolated from human skeletal muscle cells, inhibited myotube formation from myoblasts when grown in a mouse myoblast cell line C2,C12. Uninfected cultures readily converted to myotubes. Albendazole, a drug with known antimicrosporidial activity, was tested against T. hominis in C2,C12 cells. The drug was added when infection had reached 75% of C2,C12 cells, a level comparable to that obtained in heavily infected muscle in vivo. Doses of 1 ng/ml and 10 ng/ml had no effect on merogony or sporogony. In cultures exposed to 100 ng/ml albendazole, the C2,C12 cells remained in good condition while infection levels dropped to 25% over 7 weeks. Drug doses of 500 ng/ml and 1,000 ng/ml were deleterious to the host cells but some spores retained viability and were able to establish new infections once albendazole pressure was removed. T. hominis meronts exposed to 100 ng/ml albendazole mostly lacked the normally thick surface coat and its reticulate extensions. Meronts were not seen in cultures exposed to higher drug doses. Albendazole at a concentration of 100 ng/ml and higher had a profound effect on spore morphogenesis. There was erratic coiling of the polar tube, often involving the formation of double tubes, and chaotic disposition of membranes which could have been those of polaroplast. The in vitro susceptibility of T. hominis to albendazole was low in comparison with in vitro susceptibility of other microsporidia of human origin.     

Neotropical Monogenoidea 37. Redescription of Gyrodactylus superbus (Szidat, 1973) comb. n. and description of two new species of Gyrodactylus (Gyrodactylidea: Gyrodactylidae) from Corydoras paleatus and C. ehrhardti (Teleostei: Siluriformes: Callichthyidae) of Southern Brazil

Two new species of Gyrodactylus (Gyrodactylidae) are described from Corydoras paleatus (Jenyns) and Corydoras ehrhardti Steindachner (Callichthyidae) of Rio Piraquara, Municipality of Piraquara, near Curitiba, Paraná, Brazil: Gyrodactylus anisopharynx sp. n. and Gyrodactylus samirae sp. n. These species are unique among the known Neotropical species of Gyrodactylus by the combination of several characters. Gyrodactylus anisopharynx is characterised by having hooks with point evenly curved, toe moderately pointed, round convex heel, straight sloping shelf, superficial bar with anterolateral projections and male copulatory organ armed with two rows of spinelets. Two variants of G. anisopharynx, of distinct pharynx size, are recognised: forma "large-pharynx" and forma "small-pharynx". Gyrodactylus samirae is characterised by having hook with straight shaft, short slightly recurved point, truncate toe, trapezoidal heel, shelf slightly concave, orthogonal to shaft; anchors with relatively short superficial root; superficial bar with extremities lightly expanded; and male copulatory organ armed with two rows of spinelets. Paragyrodactyloides superbus (Szidat, 1973) is redescribed and transferred to Gyrodactylus based on examination of type and new specimens. Features previously considered as diagnostic for the genus are misinterpretations or primitive characters for Gyrodactylus spp.