Anagallis Arvensis Research Articles

Weed population, weed biomass and grain yield of wheat as influenced by herbicides application

A field experiment was conducted during Rabi seasons of 2015–16 and 2016–17 at Banka (Bihar) to evaluate the weed population, weed biomass and grain yield as influenced by herbicide application in wheat (Triticum aestivum L.). Seven weed species, viz. Phalaris minor, Cynodon dactylon, Chenopodium album, Oxalis purpurea, Anagallis arvensis, Medicago denticulata and Rumex dentatus infested the wheat field. Post-emergence application of sulfosulfuron 75% WG (25 g/ha) + metsulfuron-methyl 20% WP (2 g/ha) at 30 days after sowing (DAS) was very effective against broad-leaf weeds and annual grasses, and recorded significantly lower density and biomass of these weeds at 60 DAS as compared to isoproturon 75% WP 1.0 kg/ha, sulfosulfuron 75% WG 50 g/ha, metsulfuron-methyl 20% WP 4 g/ha and weedy check. Ear length, effective tillers/m2, grains/spike, grain and straw yields were also significantly higher in sulfosulfuron (25 g/ha) + metsulfuron-methyl (2 g/ha) as compared to other herbicide treatments.

Distribution Pattern, Conservation Status, and Associated Flora of the Genus Juniperus in Subalpine Pastures of the Kashmir Himalayas

Juniperus is an evergreen gymnosperm genus with a broad geographical distribution in the Northern Hemisphere. Juniperus constitutes important vegetation associations in the Himalayan highlands that have significant ecological and socioeconomic importance. This research investigated the distribution pattern, community structure, and ecosystem services provided byJuniperus -dominated subalpine vegetation in the upper Neelum Valley, Pakistan. Vegetation attributes and geographical characteristics were systematically recorded at 4 selected sites. Two species of Juniperus, Juniperus communis L. and J. excelsa M. Bieb., were found to have average importance values of 23.4 and 20.02%, respectively. J. excelsa showed an average basal area of 0.30 m2 ha−1 and an average stem density of 46.95 ha−1; J. communis had an average basal area of 0.25 m2 ha−1 and an average stem density of 33.21 ha−1. A total of 56 Juniperus-associated plant species from 29 families were recorded, with Asteraceae as the dominant family, followed by Lamiaceae, Polygonaceae, Rosaceae, Caryophyllaceae, and Apiaceae. Predominant associated species included Thymus linearis, Aster falconeri, Rosa webbiana, Berberis lyceum, Anagallis arvensis, Rumex nepalensis, Poa alpina, Bistorta affinis, and Iris hookeriana. The calculated average values were Shannon's diversity, 3.07; Simpson's diversity, 0.94; species richness, 1.11; species evenness, 0.90; and maturity index, 45.90. Hemicryptophytes were the dominant lifeform in the area (57.14%), and microphylls (46.42%) were the dominant leaf type. Overgrazing and fuelwood cutting were identified as serious threats to both Juniperus species. Restoration of the degraded juniper stands through collective efforts by government and local communities and regular monitoring is recommended.

Effect of Cover Crops, and the Management Thereof, on the Weed Spectrum in a Drip-irrigated Vineyard: 2. Weeds Growing From Grapevine Berry Set to Post-harvest

A five-year trial (2009 to 2013) was executed in a drip-irrigated seven-year-old Shiraz/101-14 Mgt vineyard established on a sandy to sandy clay loam soil at Blaauwklippen Farm (33°58’S, 18°50’E) near Stellenbosch, South Africa. Fourteen treatments, consisting of two management practices applied to five cover crop species, as well as winter-growing weeds (no cover crop) and winter-growing weeds (no cover crop) with nematicide applied in the vine row, were applied. The weeds and cover crop species were eithercontrolled chemically (CC) or mechanically (MC) during grapevine bud break, followed by full-surface chemical control during berry set (for both CC and MC treatments). Rhynchelytrum repens (Natal redtop)dominated the post-harvest pre-treatment weed spectrum in all the treatments except Eruca sativa cv. Nemat (Nemat) (MC). This species lost its post-harvest dominance from 2010 onwards. It seems that the relatively low summer rainfall during the 2010/2011 season allowed Anagallis arvensis to appear in April 2011 and dominate some of the treatments, which coincided with the disappearance of Cynodon dactylon (common couch) and Polygonum aviculare (prostrate knotweed). Digitaria sanguinalis, common couch and prostrate knotweed seemed to establish better during late summer where MC was applied. The pre-treatment average post-harvest weed stand of 5.53 t/ha was reduced to 0.53 t/ha within one season, illustrating the benefit of full-surface chemical weed control applied during grapevine berry set.

Mechanical weed control in organic winter wheat

Three field experiments were carried out in organic winter wheat in three consecutive years (exp. 1, 2005-06; exp. 2, 2006-07; exp. 3, 2007-08) in central Italy (42°57' N - 12°22' E, 165 m a.s.l.) in order to evaluate the efficacy against weeds and the effects on winter wheat of two main mechanical weed control strategies: 1) spring tine harrowing used at three different application times (1 passage at T1; 2 passages at the time T1; 1 passage at T1 followed by 1 passage at T1 + 14 days) in the crop sowed at narrow (traditional) row spacing (0.15 m) and 2) split-hoeing and finger-weeder, alone and combined at T1, in the crop sowed at wider row spacing (0.30 m). At the time T1 winter wheat was at tillering and weeds were at the cotyledons-2 true leaves growth stage. The experimental design was a split-plot with four replicates. Six weeks after mechanical treatments, weed ground cover (%) was rated visually using the Braun–Blanquet cover-abundance scale; weeds on three squares (0.6 x 0.5 m each one) per plot were collected, counted, weighed, dried in oven at 105 °C to determine weed density and weed above-ground dry biomass. At harvest, wheat ears density, grain yield, weight of 1000 seeds and hectolitre weight were recorded. Total weed flora was quite different in the three experiments. The main weed species were: <em>Polygonum aviculare</em> L. (exp. 1 and 2), <em>Fallopia convolvulus</em> (L.) Á. Löve (exp. 1 and 3), <em>Stachys annua</em> (L.) L. (exp. 1), <em>Anagallis arvensis</em> L. (exp. 2), <em>Papaver rhoeas</em> L. (exp.3), <em>Veronica hederifolia</em> L. (exp. 3). In the winter wheat sowed at narrow rows, 2 passages with spring-tine harrowing at the same time seems to be the best option in order to reconcile a good efficacy with the feasibility of treatment. In wider rows spacing the best weed control was obtained by splithoeing alone or combined with finger-weeder. The grain yield, on average 10% higher in narrow rows, the lower costs and the good selectivity of spring-tine harrowing treatments seems to suggest the adoption of narrow rows spacing in wheat in organic and low-input farming systems.

Antifungal activity and cytotoxicity of extracts and triterpenoid saponins obtained from the aerial parts of Anagallis arvensis L.

Ethnopharmacological relevanceAnagallis arvensis L. (Primulaceae) is used in argentinean northwestern traditional medicine to treat fungal infections. We are reporting the isolation and identification of compounds with antifungal activity against human pathogenic yeast Candida albicans, and toxicity evaluation. Aim of the studyto study the antifungal activity of extracts and purified compounds obtained form A. arvensis aerial parts, alone and in combinations with fluconazole (FLU), and to study the toxicity of the active compounds. Materials and methodsDisk diffusion assays were used to perform an activity-guided isolation of antifungal compounds from the aerial parts of A. arvensis. Broth dilution checkerboard and viable cell count assays were employed to determine the effects of samples and combinations of FLU + samples against Candida albicans. The chemical structures of active compounds were elucidated by spectroscopic analysis. Genotoxic and haemolytic effects of the isolated compounds were determined. ResultsFour triterpenoid saponins (1–4) were identified. Anagallisin C (AnC), exerted the highest inhibitory activity among the assayed compounds against C. albicans reference strain (ATCC 10231), with MIC-0 =1µg/mL. The Fractional Inhibitory Concentration Index (FICI=0.129) indicated a synergistic effect between AnC (0.125µg/mL) and FLU (0.031µg/mL) against C. albicans ATCC 10231. AnC inhibited C. albicans 12–99 FLU resistant strain (MIC-0 =1µg/mL), and the FICI=0.188 indicated a synergistic effect between AnC (0.125µg/mL) and fluconazole (16µg/mL). The combination AnC+ FLU exerted fungicidal activity against both C. albicans strains. AnC exerted inhibitory activity against C. albicans ATCC 10231 sessile cells (MIC50=0.5µg/mL and MIC80=1µg/mL) and against C. albicans 12–99 sessile cells (MIC50=0.75µg/mL and MIC80=1.25µg/mL). AnC exerted haemolytic effect against human red blood cells at 15µg/mL and did not exerted genotoxic effect on Bacillus subtilis rec strains. ConclusionsThe antifungal activity and lack of genotoxic effects of AnC give support to the traditional use of A. arvensis as antifungal and makes AnC a compound of interest to expand the available antifungal drugs.

Efficacy of Calcium Borogluconate and Lime Water Therapy in Anagallis arvensis Intoxicated Cattle

Anagallis arvensis is a common weed seen in agricultural fields in Marathwada region of Maharashtra state. This weed contains different poisonous principles like glycosides, volatile oil, saponin (anagallin), tannin, and oxalates. In scarcity of fodder, cattle in some regions had exposure to Anagallis arvensis weed causing oxalic acid toxicity and nephrotic syndrome. Twenty Anagallis arvensis affected cattle were randomly distributed in two groups (Group-I; n=10 and Group-II; n=10). Anagallis arvensis intoxicated cattle of Group-I were subjected to primary therapy of calcium borogluconate @ 450 ml per cattle slow I/V, whereas, Group II cattle were treated with combination of calcium borogluconate @ 450 ml per cattle and lime water (1 kg of lime mixed to make 10 litres of water and one litre of this solution was administered twice a day) therapy. Based on improvement in clinical, haematological, biochemical parameters and recovery; parentral calcium borogluconate and oral lime water therapy along with standard supportive regimen was found highly efficacious in the treatment of Anagallis arvensis toxicity.

Evaluation of herbicide combinations for controlling complex weed flora in wheat

A field experiment was conducted during the Rabi seasons of 2014–15 and 2015–16 on a silty clay loam soil at Palampur. Avena ludoviciana (36.3%), Phalaris minor (27.5%), Lolium temulentum (13.9%), Anagallis arvensis (10%) and Coronopus didymus (6.9) were the major weeds. Herbicide combinations (pendimethalin 1.0 kg/ha + metribuzin 175 g/ha, pendimethalin 1.0 kg/ha fb sulfosulfuron 18 g/ha, sulfosulfuron 20 g/ha + metsulfuron 4 g/ha, pinoxaden 60 g/ha + metsulfuron 4 g/ha, clodinafop 60 g/ha + metsulfuron 4 g/ha, isoproturon 1.0 kg/ha + 2, 4-D 0.5 kg/ha) were superior to sole application of herbicides (pendimethalin 1.25 kg/ha, sulfosulfuron 25 g/ha, metribuzin 210 g/ha and clodinafop 60 g/ha) in reducing weed count and dry weight and increasing plant height, number of tillers, crop dry matter, yield attributes and yield of wheat. Clodinafop + metsulfuron, pinoxaden + metsulfuron and pendimethalin fb metsulfuron being better than other combinations gave 28.6, 22.5 and 23.1% higher grain yield of wheat over hand weeding twice. Weeds reduced the grain yield by 51.9%. With unit increase in weed count per m2, the wheat grain yield was decreased by 13.3 kg/ha. The cost of weed control under herbicidal treatments was 9.0–28.9% of that under hand weeding lowest being under metribuzin and highest under pendimethalin fb sulfosulfuron. Clodinafop + metsulfuron gave the highest net returns due to weed control and marginal benefit: cost ratio (MBCR). Clodinafop + metsulfuron resulted in highest weed control efficiency (WCE), weed control index (WCI), crop resistance index (CRI), treatment efficiency index, crop intensity index and weed index. Weed management index, agronomic management index and integrated weed management index were highest under sulfosulfuron followed by clodinafop + metsulfuron. Based on overall impact index clodinafop + metsulfuron, pinoxaden + metsulfuron, sulfosulfuron + metsulfuron, pendimethalin fb sulfosulfuron and pendimethalin + metribuzin were recommended for effective weed management in wheat under mid hill conditions of Himachal Pradesh.

Optimization rate of pinoxaden + clodinafop-propargyl for weed control in wheat

A field experiment was conducted during 2011–12 and 2012–13 at GB. Pant University of Agriculture & Technology, Pantnagar to study the effect of different rates of pre-mix of pinoxaden 2.53% + clodinafop-propargyl 2.53% on population and growth of weeds and grain yield of wheat. Major weed species identified in the experiment were Phalaris minor, Avena spp., Chenopodium album, Anagallis arvensis, Polygonum plebeium, Melilotus indica, Coronopus didymus during both the years. The lowest density and biomass of grassy weeds were recorded with pinoxaden 2.53% + clodinafop- propargyl 2.53% at 60 g/ha. However, it was ineffective against broad-leaf weeds. Maximum grassy weed control efficiency (100%) was observed with pinoxaden + clodinafop-propargyl at 60 g/ha closely followed by its lower dose applied at 50 g/ha and pinoxaden at 50 g/ha. Pre-mix of pinoxaden 2.53% + clodinafop-propargyl 2.53% at 60 g/ha produced highest grain yield (4.5–4.6 t/ha). Uncontrolled weeds caused 55.7 and 52.2% reduction in grain yield of wheat when compared with weed free conditions during 2011–12 and 2012–13.

Invasion of Different Weeds on Gladiolus and their Control by Herbicides

Weeds are defined as plants growing where they are not desired. Presence of weeds highly effects the growth and development of desirable plants. Present study was carried out at Floriculture Research Area, University of Agriculture Faisalabad. The experiment was laid out in randomized complete block design with three replications. Five herbicide treatments were applied in three replications to the gladiolus variety “white prosperity”. By comparing results of pre and post emergence herbicide applications, it was observed that pre emergence treatments gave better results regarding weed control due to reduced competition between weed plants and crop plants. Pendimethalin applied at 12ml/litre was found to be the most effective treatment and controlled all weeds except Cyperus rotundus . Average number of plants and weed inhibition percentage of Cyperus rotundus in one foot square area were, 15.22 (39%), Convolvulus arvensis , 0.89 (77%), Coronopus didymus , 0.33 (91%), Chenopodium album , 0.22 (98%), Anagallis arvensis , 0.22 (98%), Conyza stricta , 0.89 (85%), Stellaria media , 0.22 (98%), Poa annua , 0.0 (100%), Melilotus indica , 0.22 (98%). Study revealed that Cyperus rotundus was efficiently controlled by S metolachlore than Pendimethalin where only average (2.22) numbers of plants were found in one square foot area and best weed inhibition percentage was upto (91%) for Cyperus rotundus.

Weed management using post-emergence herbicides in chickpea (Cicer arietinum) + mustard (Brassica juncea) intercropping system

A field study was conducted at Indian Institute of Pulses Research, Kanpur during winter season of 2008-09 and2009-10 to study the weed control efficiency of different weed management practices including post-emergence herbicides in chickpea (Cicer arietinum L.) + mustard (Brassica juncea L.) intercropping system. Treatment comprised two different doses of quizalofop-ethyl, imazethapyr and chlorimuron-p-ethyl along with pendimethalin and manual weeding. Cyperus rotundus, Anagallis arvensis, Chenopodium album, Polygonum plebejum and Phalaris minor were the dominant weeds. Cyperus rotundus was the most dominant weeds with highest relative density and relative dry weight. The toxic effect of imazethapyr and chlorimuron was recorded on both chickpea and mustard. Among herbicide treatments, significantly lowest weed density and weed dry weight and highest weed control efficiency, weed control index, nodule specific weight and plant dry matter were recorded in quizalofop-ethyl @ 60 g/ha. Similarly, higher chickpea and mustard yield, system productivity, net return and B/C ratio were recorded in quizalofop-ethyl @ 60 g/ha and manual weeding.

Ecophysiological characteristics of five weeds and a wheat crop in the Indo-Gangetic Plains, India.

The objective of this research was to compare selected ecophysiological parameters for a wheat crop found in the Indo‐Gangetic Plains of India and its five dominant weeds. The dominant and regionally ubiquitous weeds in the wheat field that was selected for the study were Anagallis arvensis, Chenopodium album, Melilotus albus, Phalaris minor and Rumex dentatus. Taller weeds, such as C. album and P. minor, constituted one group along with the crop, with a low photosynthetic rate, specific leaf area, leaf nitrogen mass basis, chlorophyll content, photosynthetic nitrogen‐use efficiency and leaf area ratio, in comparison to shorter weeds, such as A. arvensis, M. albus and R. dentatus, which formed another group with a high photosynthetic rate, specific leaf area, leaf nitrogen mass basis, chlorophyll content, photosynthetic nitrogen‐use efficiency and leaf area ratio. Interspecific variations in the photosynthetic rate were driven mainly by variability in the specific leaf area and leaf nitrogen content. The taller weeds and the crop had a low specific leaf area later in the season, whereas the smaller weeds had a relatively high specific leaf area, which might be an adaptation to the shaded environment below the canopy. The result indicates that any weed management in the wheat fields of the Indo‐Gangetic Plains will need two different approaches because of the different strategies followed by the two weed groups that were identified in the present study.

Integrated Weed Management in Potato Using Straw Mulch and Atrazine

Potato (Solanum tuberosum) is one of four major food crops in the world. Weed control is a major component in potato production and has been accomplished using different methods, including but not limited to the use of herbicides and straw mulch. A combination of preemergence herbicide and straw mulch may improve weed control; however, no information is available for combining both methods, along with their effects on weed control, weed density, and potato tuber yields. The objective of this study was to evaluate weed control in potato using atrazine or straw mulch applied alone at different rates or in combination. A field experiment was conducted for 4 years from 2006 to 2010 in Ludhiana, Punjab, India. Common weeds included burclover (Medicago arabica), common lambsquarters (Chenopodium album), littleseed canarygrass (Phalaris minor), purple nutsedge (Cyperus rotundus), scarlet pimpernel (Anagallis arvensis), swinecress (Coronopus didymus), and toothed dock (Rumex dentatus). Results suggested that atrazine applied alone was not very effective and resulted in 0% to 78% control depending on the weed species being investigated at 30 days after treatment (DAT). Straw mulch applied alone at any rate provided ≥90% control of toothed dock, but control of other weed species was variable. A combination of atrazine and straw mulch at any rate usually resulted in >90% weed control at 30 DAT, except for swinecress and purple nutsedge. This treatment combination also resulted in weed density as low as 0 plant/m2 for common lambsquarters, scarlet pimpernel, and toothed dock. Potato tuber weight and yield was significantly higher in all treatments compared with untreated control without difference among them. It is concluded that a combination of straw mulch and atrazine can provide effective weed control in potato.

Evaluation of metsulfuron methyl and clodinafop alone and in combination with other herbicides against weeds in wheat (Triticum aestivumL.)

A field investigation was carried out during rabi seasons of 2012 and 2013 at Palampur with nine treatments comprising three doses of metsulfuron methyl (2, 4 and 8 g/ha), two doses of clodinafop (60 and 120 g/ha), two combinations i. e. clodinafop+metsulfuron methyl 60+4 g/ha and isoproturon+2, 4-D 1.0+0.5 kg/ha and weedy check to evaluate their performance against mixed weed flora in wheat. Experimental field was mostly infested with grassy weeds with Phalaris minor as the most dominant weed constituting 48.03% of total weed flora. Lolium temulentum, Avena fatua and Vicia sativa were the other important weeds. Among different herbicides, clodinafop 120 g/ha being statistically alike with its lower dose i. e 60 g/ha resulted in significantly lower count of grassy weeds viz., P. minor, L. temulentum, A. fatua at 90 and 120 DAS. Combination of clodinafop+ metsulfuron methyl 60+4 g/ha was the next best in this regard. Same herbicide i. e. clodinafop120 g/ha recorded significantly lower dry matter of all these grassy weeds at both the stages of observation. However, clodinafop+metsulfuron methyl 60+4 g/ha was at par with it for reducing the dry matter of A. fatua at both the stages of observation and P. minor and L. temulentum at 120 DAS and also with clodinafop 60 g/ha for L. temulentum at both stages and for A. ludoviciana and P. minor at 90 and 120 DAS, respectively. Among different herbicides, tank mix application of clodinafop+metsulfuron methyl 60+4 g/ha and isoproturon+2, 4-D 1.0+0.5 kg/ha being at par with metsulfuron methyl 4 and 8 g/ha resulted in recording significantly lower weed count and dry matter of V. sativa and Anagallis arvensis at both stages of observation. Similarly, both these tank mixtures at both the stages and clodinafop 60 and 120 g/ha at 120 DAS being at par with each other were significantly superior for controlling other weeds. Tank mix application of clodinafop+metsulfuron methyl 60+4 g/ha being at par with clodinafop 60 and 120 g/ha resulted in recording significantly lower weed count and weed dry matter of total weeds. Clodinafop applied at either 60 or 120 g/ha being at par with both combinations of herbicides i. e. clodinafop+metsulfuron methyl 60+4 g/ha and isoproturon+2, 4-D 1.0+0.5 kg/ha produced significantly higher grain, straw and biological yield of wheat. Clodinafop 60 g/ha was the best in recording highest net returns of Rs. 29385/ha with B: C ratio of 1.21, followed by clodinafop+metsulfuron methyl 60+4 g/ha and isoproturon+2, 4-D 1.0+0.5 kg/ha having net returns of Rs. 29364 and 28386/ha, respectively, with similar B: C ratio of 1.19.

Effect of weed control and phosphorus sources on productivity of wheat (Triticum aestivum)

A field experiment was conducted to study the effect of herbicides and phosphorus sources on productivity of wheat (Triticum aestivum L.). The weed flora at site were Chenopodium murale, C. album, Anagallis arvensis, Convolvulus arvensis, Melilotus indica, Spergulla arvensis, Malva parviflora, Fumaria parviflora, Rumex obtusifolius and Coronopus didymus among broadleaf weeds and Phalaris minor in grassy weed. The experiment consisted of eight herbicide (weedy check, 2,4-D at 500 g ha-1, triasulfuron at 15 g ha-1, carfentrazone at 20 g ha-1, isoproturon at 750 g ha-1, 2,4-D + isoproturon at 500 + 750 g ha-1, triasulfuron + isoproturon at 15 + 750 g ha-1, carfentrazone + isoproturon at 20 + 750 g ha-1) and three phosphorus sources (DAP, SSP and PROM) making twenty four treatment combinations. These treatments were evaluated in randomized block design with four replications. Amongst the weed control treatments tank mixture of carfentrazone + isoproturon (20 + 750 g ha-1) resulted in complete elimination of all the broadleaf weeds except Convolvulus arvensis. Isoproturon and its tank mixture with other reduced weed density and dry matter of Phalaris minor significantly than weedy check and rest of the treatments. Tank mix application of herbicides tended to reduce weed dry matter significantly in comparison to singly applied herbicides, however, carfentrazone + isoproturon resulted in minimum weed dry matter (11.29 kg ha-1) and highest weed control efficiency (97.33%). Consequently, it produced significantly higher grain (5816 kg ha-1) and straw (8904 kg ha-1) yields and net returns ( 65267 ha-1) compared to other treatments. This mixture recorded significantly lower N, P and K uptake by weeds with concomitant 84.9, 119.5 and 73.3 % higher uptake of these nutrient elements by wheat crop over weedy check.

Ecological and Geographical distribution of species and genera of Primulaceae in Iraq

The present research deal with ecological and geographical distribution of species and genera of Primulaceae in Iraq. The results were revealed that species distributed in the north , north-east and west of Iraq. Anagallis arvensis L. is the most prevalent species tolerant to different environmental conditions, while the species of Primula L. characterized as less widespread and limited in one District. In addition, the districts Rawanduz (MRO) and Sulaymaniyah (MSU) have ranked first in distribution of the species on geographical districts with (75%), while the districts southern desert (DSD) and Basra (LBA) in last place with (16.7%). Maps for geographical distribution for all species were illustrated.

Ecological and Geographical distribution of species and genera of Primulaceae in Iraq

The present research deal with ecological and geographical distribution of species and genera of Primulaceae in Iraq. The results were revealed that species distributed in the north , north-east and west of Iraq. Anagallis arvensis L. is the most prevalent species tolerant to different environmental conditions, while the species of Primula L. characterized as less widespread and limited in one District. In addition, the districts Rawanduz (MRO) and Sulaymaniyah (MSU) have ranked first in distribution of the species on geographical districts with (75%), while the districts southern desert (DSD) and Basra (LBA) in last place with (16.7%). Maps for geographical distribution for all species were illustrated.

Pre-harvest Weeds of a Wheat Field at Biratnagar, Nepal

Sixty eight species of weeds belonging to 22 families and 59 genera were recorded from a wheat field at Biratnagar during the pre-harvest condition. Based on species prevalence the dominant weed families were Asteraceae (17 species), Poaceae (13 species) and Fabaceae (6 species). Anagallis arvensis, Crepis japonica, Grangea maderaspatana, Polygonum plebeium were abundant and Fumaria indica, Leucas lavandulifilia, Rumex dentatus, Vicia angustifolia, V. hirsuta and V. tetrasperma were common species of weeds. DOI: http://dx.doi.org/10.3126/on.v11i2.9597 Our Nature 2013, 11(2): 187-191

Intraspecific variation of phyllotaxis stability in Anagallis arvensis

Qualitative transformations of phyllotaxis in <em>Anagallis arvensis</em> occur typically during the generative phase of development. In the vegetative phase phyllotaxis usually does not change. An exception to this rule is one peculiar population of <em>Anagallis arvensis</em>, belonging to a pink-flowered form carnea, in which phyllotaxis often transforms in both the generative and vegetative phase of development. The presence of a relatively large number of vegetative transitions, virtually absent in two control red-flowered populations of form arvensis, is accompanied also by the higher frequency of generative transitions. This might be a result of a genetically determined instability of shoot apex geometry. It has been proved experimentally that changing conditions of growth affect the transition frequencies and the time lapse from the beginning of either the vegetative or generative phase to the transition (measured in plastochrons). A comparison of two types of transitions shows that divergence changes are less abrupt in vegetative transitions. The differences between the two types also pertain to the vertical spacing of leaves and to the pattern formed by leaf bases and wings on the stem surface in the transition zone.

Phyllotaxis of vegetative shoots of Anagallis arvensis L. treated in vitro with 6-benzylaminopurine

Application of 6-benzylaminopurine (BA), a synthetic cytokinin, to the growth medium in vitro stimulates the formation of adventitious shoots on stem explants of <em>Anagallis arvensis</em>. They regenerate from dedifferentiating epidermal cells of stem internodes. The process starts from periclinal and anticlinal divisions in a few of neighbouring cells. The amount of adven-titious shoots increases with an increasing BA concentration. The BA treatment also affects phyllotaxis, but only of adventitious shoots, and not of normal lateral shoots developing in leaf axils. Leaf arrangement on adventitious shoots is always variable, even on the control medium. Generally, patterns observed in case of in vitro shoots do not differ from those reported earlier for intact <em>A. arvensis</em> plants. BA treatment also leads to the teratologic development, i.e. fasciation and the formation of abnormally shaped leaves, but again in adventitious rather than in normally developing shoots. We postulate that the variability of phyllotaxis characteristic for adventitious shoots and their responce to BA treatment, result from the fact that their apical meristems develop de novo from initially unorganised meristematic centres, whereas meristems of normally developing lateral shoots are well organised from the time of their initiation.

In vivo labelling of Anagallis arvensis L. cells with green fluorescent protein

A few methods only enable to follow the fate of plant cells in vivo. One of the most promising is using the Green Fluorescent Protein (GFP). In our preliminary study we set up the experimental system enabling labelling of <em>Anagallis arvensis</em> cells with this marker. We prepared an expression plasmid containing red-shifted <em>gfp</em> with optimised translation start site context, under the control of CaMV 35S transcription promoter. The construct was introduced into <em>A. arvensis</em> cells by particle bombardment. We developed two methods of material preparation for this transformation: in vitro cultured stem internodes with regenerating adventitious shoots (the earliest stages of regeneration); and shoot tips with temporarily exposed apices. The reflected light fluorescence microscope Olympus with the set of filters U-MNB designed for fluorescein detection enables the observation of GFP fluorescence. Both ordinary epidermal cells and stomata guard cells were transformed. Their fluorescence was observed for up to 14 days. Artefacts (autofluorescence of glandular trichomes and faint green glowing of meristematic tissue) could be overcome by the optimisation of the filter set.