Bacteria wilt of Casuarina equisetifolia in India

Pseudomonas solanacearum (Smith) was consistently isolated from the wilted plants of Casuarina equisetifolia. The isolate gave positive reaction to oxidase, catalase and gas production from nitrate and negative reaction for arginine dihydrolase and acid was produced from various carbohydrates. Wilt produced on tomato, egg plant and capsicum indicated that the pathogen belongs to Race I and Biovar III of P. solanacearum which is a new record from India.     

Effects of leaf area and auxin on rooting and growth of rooted stem cuttings of neem

Green stem cuttings, obtained from 2-year old managed stockplants, with 30, 50 or 100% leaf area were rooted in a non-mist propagator following treatment with 0, 0.2, 0.4 or 0.8% IBA solution. The rooted cuttings were transferred to polythene pots and grown in a nursery for 12 weeks. Rooting percentages of IBA treated cuttings did not significantly differ from those of control cuttings. Likewise leaf area did not significantly influence the percentage of cuttings that rooted. The effects of leaf area and/or IBA treatment in the propagation unit were manifested on the growth of rooted cuttings in polythene pots. Number of roots increased with the increase in IBA concentration and this response was enhanced by increasing leaf area. Root biomass increased with the increase in leaf area even in the control cuttings. Root development was highly influenced by the leaf area and IBA, and hence the growth of rooted cuttings. Cuttings treated with 0.2 or 0.4% IBA at 100% leaf area yielded the best performing rooted cuttings.     

Hyperhydricity in apple: ultrastructural and physiological aspects

We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants. Morphological, anatomical and ultrastructural differences between healthy leaf tissues obtained from greenhouse-grown plants and healthy and hyperhydric leaves obtained from shoots raised from nodal shoot explants in a bioreactor were investigated by electron microscopy and confocal laser scanning microscopy. Compared with healthy leaves, hyperhydric leaves showed abnormal, often discontinuous development of the epidermis and cuticle. Stomata were malformed. The leaf lamina appeared thickened and was characterized by poor differentiation between the palisade and spongy mesophyll tissue. Hyperhydric leaves had a significantly lower chloroplast number per cell and chloroplasts showed reduced thylakoid stacking compared with healthy leaves. Hyperhydricity resulted in a general decrease in concentrations of reduced and oxidized pyridine nucleotides, reflecting a reduction in metabolic activity. The activities of antioxidant enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were higher in hyperhydric leaves than in healthy leaves, indicating that hyperhydricity was associated with oxidative stress. Chlorophyll fluorescence measurements provided evidence of oxidative damage to the photosynthetic machinery in hyperhydric leaves: photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were all lower in hyperhydric leaves compared with healthy leaves.     

Molecular simulations probing Kushecarpin A as a new lipoxygenase inhibitor

Zizyphus oxyphylla Edgew is used in Pakistan as a folk medicinal remedy for inflammatory conditions, pains especially rheumatic pain, fevers, allergy and diabetes. The aim of the current study was to scientifically validate the folk use of Z. oxyphylla Edgew by using the isolated compound in vitro and in vivo levels. Kushecarpin A was isolated from ethyl acetate fraction of the plant crude extract. Molecular docking simulations predicted Kushecarpin A as a potential new lipoxygenase (LOX) inhibitor. Kushecarpin A showed significant lipoxygenase inhibition (IC50: 7.2 ± 0.02 μM) thus validated computational prediction. It also exhibited significant and highly significant inhibition (p < 0.05 and p < 0.01) of carrageenan-induced hind paw oedema at the doses of 5, 10 and 20 mg/kg. Kushecarpin A seems to be a potentially new anti-inflammatory compound responsible for anti-inflammatory activities of Z. oxyphylla Edgew. In vitro and in vivo anti-inflammatory inflammatory activities were found in good agreement with the folk medicinal use of Z. oxyphylla Edgew in inflammatory disorders.     

Kaurane-type diterpenoids from Chromoleana odorata, their X-ray diffraction studies and potent α-glucosidase inhibition of 16-kauren-19-oic acid

A new diterpenoid, 15-angeloyloxy-16,17-epoxy-19-kauronic acid (1), along with five known metabolites, 16-kauren-19-oic acid (2), 6′-hydroxy-2′,3′,4,4′-tetramethoxychalcone (3), isosakuranetin (4), acacetin (5), and kaempferide (6) was isolated from the organic extracts of the roots of Chromoleana odorata. Their structures were determined by spectroscopic evidences. The structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction studies. Compound 2 exhibited significant α-glucosidase inhibitory and antibacterial activities against Escherichia coli and Bacillus subtilis.     

Preference and performance of <Emphasis Type="Italic">Plutella xylostella</Emphasis> (L.) (Lepidoptera: Plutellidae) on canola cultivars

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important insect pest of canola, Brassica napus L., in Ardabil, Iran. Host plant resistance is an essential component of integrated management of P. xylostella. We investigated the preferences and performance of P. xylostella on nine commercial cultivars of canola, namely Zarfam, RGS003, Adder, Okapi, Opera, Hyola401, Ebonite Option500 and Elite under greenhouse conditions at 23 ± 1°C, 50 ± 5% RH and 14L:10D. In free-choice situation, oviposition was lowest on Opera (23.5) and highest on Zarfam (44.7). In the life table study, fecundity of new generation female moths was lowest on Opera (95.4) and highest on Adder (145.7). Survival from egg to adult was significantly lower on Opera, Option500 and Hyola401 than on other tested cultivars. The intrinsic rate of natural increase (r _m) and population growth rate (λ) were lowest on Opera and highest on Zarfam. The generation time (T) was shortest on Zarfam (17.2 days) and longest on Hyola401 (19.9 days) whereas doubling time (DT) was longest on Opera (3.9 days) and shortest on Zarfam (3.0 days). Our results clearly suggest that Opera was the most resistant host among the tested cultivars and has the potential to be used in the integrated management of P. xylostella.     

Potential for using Datura alba leaf extracts against two major stored grain pests, the khapra beetle Trogoderma granarium and the rice weevil Sitophillus oryzae

Various plants are well known for their insecticidal activity and their use was maintained for millennia throughout all the agricultural regions of the world. In a current context, the use of Botanical insecticides represents one of the best alternatives to chemicals for the development of environmental-friendly strategies for stored grain pest control. Datura alba Nees is a plant found extensively in the warmer regions of the world and it is used as a medicinal plant. This study aims to assess the contact toxicity and the trans-generational effect of D.?alba leaf extract (DLE) against two important insect pests on stored rice, Trogoderma granarium and Sitophilus oryzae, under laboratory conditions. Filter papers were soaked in three DLE concentration solutions and in two control treatments: water and acetone. The survivor specimens (F₀) were transferred to a new untreated feeding substrate and the population build up of the two following generations (F₁ and F₂) were counted after 30 and 60?days, respectively. The highest DLE concentration (2.5?%) induced the significantly highest mortality with 33.5 and 45?% mortality in T.?granarium and S.?oryzae after 7?days of exposure, respectively. The DLE long-term effect toward both tested species was also proved by the high demographic decrease in the F₂ generations, when compared to control groups. This study is the first step toward establishing a scientific basis for the effective application of D.?alba plant materials as biorational tools to control stored grain pests.     

Zum saisonalen Auftreten der Baumwolleule,Spodoptera littoralis (Boisd.) (Lep., Noctuidae) und ihrer Kernpolyedrose (NPV) in verschiedenen Distrikten Ägyptens

Infection rates of the nuclear polyhedrosis virus (NPV) in the cotton leafworm,Spodoptera littoralis larvae were assessed from 1985 through 1986 in clover fields at El-Behiera, El-Fayoum and El-Gharbia governorates. Infection rates of the pathogen were highest near the end of spring when the cotton leafworm larval populations were increasing. For the different governorates, the percentages of virus infection were almost higher in 1985-season than in 1986. El-Fayoum-larval population was the most infected by NPV followed by El-Gharbia and El-Behiera-populations, respectively. There was a positive correlation between infection rates of NPV on one hand, and density of larva and ambient temperature on the other.