Streptomycin- and Penicillin-induced Inhibition of Growth and Pigment Production in Blue-green Algae and Production of Strains of Anacystis nidulans Resistant to these Antibiotics

Relatively low concentrations of streptomycin inhibited thegrowth of Anacystis nidulans and Anabaena variabilis. The productionof chlorophyll, carotenoid, and phycocyanin pigments in thesealgae was significantly but reversibly inhibited by streptomycin.Strains of Anacystis nidulans that are resistant to streptomycinand penicillin were produced by serially subculturing the algain gradually increasing concentrations of the respective antibiotic.These strains seem stable. Evidence which suggests that theresistant strains originate primarily by mutation is presented.     

Natural enemies of Toxoptera aurantii (Boy.) (Homoptera: Aphididae) on cocoa in Ghana

Natural enemies of the black citrus aphid, Toxoptera aurantii (Boy.), on cocoa in Ghana are identified. Biology of some of the natural enemies is followed. Behaviour of the coccinellid and syrphid predators is studied in detail. Effectiveness of the predators in reducing the aphid populations is discussed.     

Witch Hunts, Herbal Healing, and Discourses of Indigenous Ecodevelopment in North India: Theory and Method in the Anthropology of Environmentality

ABSTRACT  In this article, we examine the environmental thought and practice of indigenous peoples living in and around a wildlife sanctuary in North India. Analysis reveals that those religious specialists (such as shamans) who possess knowledge of herbal healing are more committed than other villagers to preventing or mitigating the overharvesting of natural resources. To explain these results, reference is made to a specific juncture of native traditions and modern conditions and in particular to an intersection of local economies with global discourses of "ecodevelopment." Drawing on theories and methods from political ecology and cultural psychology, we present a framework for testing the extent that local actors—in this case, shamanic and herbalist healers—are differently positioned to resist or accommodate state and parastate structures of "environmentality" than are other villagers.     

Effect of Gibberellic Acid and Some Phenols on Flowering of Impatiens balsamina, a Qualitative Short-day Plant

GA₃ as well as SA (salicylic acid) and β-N (β-naphthol) induce floral buds in Impatiens balsamina under strictly non-inductive photoperiods. The floral bud initiation is accelerated when 1 mg/1 SA is used in combination with 100 mg/1 GA₃. 100 mg/1 GA₃+ 1 mg/1 SA and 100 mg/1 GA₃+ 100 mg/1 β-N increase the number of floral buds as compared with 100 mg/1 GA₃ alone.     

Effect of Acetone on the Induction and Breakage of Secondary Dormancy in Seeds of Cucumber

The dark-germinating seeds of cucumber (Cucumis sativus L. cv.Saharanpur Long green) developed secondary dormancy when giventwo brief far-red light (FR) irradiations during a 4 d incubationin osmoticum at 20°C. Acetone treatment of seeds was foundnot only to break FR-induced dormancy but also to prevent itsdevelopment. The progressive effect of increasing the durationof treatment or the concentrations of acetone, as well as anappreciable activity of the latter, irrespective of its applicationto dry or hydrated seeds, is consistent with the Taylorson hypothesisof anaesthetic action at the membrane level. Contrary to thegeneral consensus that it is only the cells of the embryo whichrespond to an active dormancy-breaking factor, termination ofdormancy as well as prevention of its development by acetonein cucumber seeds was accompanied by a striking change in thepermeability of the cell membranes of the perisperm-endospermenvelope enclosing the embryo. This change in the permeabilityof the cell membranes brought about by acetone appeared to bepermanent in nature as it was not affected by hydration or dehydrationof the treated seeds. Key words: Acetone, anaesthetic substances, secondary seed dormancy, triphenyl tetrazolium chloride, benzyladenine, Evan's blue     

Ecology of cotton stainers (Heteroptera: Pyrrhocoridae) in southern Ghana

An account is given of the ecology of four species of Dysdercus in southern Ghana. Succession of host plants, host preference and migration is studied. Colony structure is examined. Natural enemies are investigated. Mimetic resemblance of the resident predator to a particular species of host Dysdercus is studied. Experiments on the palatibility of Dysdercus species to mammalian predators are discussed.     

Genetics of flowering time in bread wheat <Emphasis Type="Italic">Triticum aestivum</Emphasis>: complementary interaction between vernalization-insensitive and photoperiod-insensitive mutations imparts very early flowering habit to spring wheat

Time to flowering in the winter growth habit bread wheat is dependent on vernalization (exposure to cold conditions) and exposure to long days (photoperiod). Dominant Vrn-1 (Vrn-A1, Vrn-B1 and Vrn-D1) alleles are associated with vernalization independent spring growth habit. The semidominant Ppd-D1a mutation confers photoperiod-insensitivity or rapid flowering in wheat under short day and long day conditions. The objective of this study was to reveal the nature of interaction between Vrn-1 and Ppd-D1a mutations (active alleles of the respective genes vrn-1 and Ppd-D1b). Twelve Indian spring wheat cultivars and the spring wheat landrace Chinese Spring were characterized for their flowering times by seeding them every month for five years under natural field conditions in New Delhi. Near isogenic Vrn-1 Ppd-D1 and Vrn-1 Ppd-D1a lines constructed in two genetic backgrounds were also phenotyped for flowering time by seeding in two different seasons. The wheat lines of Vrn-A1a Vrn-B1 Vrn-D1 Ppd-D1a, Vrn-A1a Vrn-B1 Ppd-D1a and Vrn-A1a Vrn-D1 Ppd-D1a (or Vrn-1 Ppd-D1a) genotypes flowered several weeks earlier than that of Vrn-A1a Vrn-B1 Vrn-D1 Ppd-D1b, Vrn-A1b Ppd-D1b and Vrn-D1 Ppd-D1b (or Vrn-1 Ppd-D1b) genotypes. The flowering time phenotypes of the isogenic vernalization-insensitive lines confirmed that Ppd-D1a hastened flowering by several weeks. It was concluded that complementary interaction between Vrn-1 and Ppd-D1a active alleles imparted super/very-early flowering habit to spring wheats. The early and late flowering wheat varieties showed differences in flowering time between short day and long day conditions. The flowering time in Vrn-1 Ppd-D1a genotypes was hastened by higher temperatures under long day conditions. The ambient air temperature and photoperiod parameters for flowering in spring wheat were estimated at 25°C and 12 h, respectively.     

Identification and functional characterization of effectors in expressed sequence tags from various life cycle stages of the potato cyst nematode Globodera pallida

In this article, we describe the analysis of over 9000 expressed sequence tags (ESTs) from cDNA libraries obtained from various life cycle stages of Globodera pallida . We have identified over 50 G. pallida effectors from this dataset using bioinformatics analysis, by screening clones in order to identify secreted proteins up-regulated after the onset of parasitism and using in situ hybridization to confirm the expression in pharyngeal gland cells. A substantial gene family encoding G. pallida SPRYSEC proteins has been identified. The expression of these genes is restricted to the dorsal pharyngeal gland cell. Different members of the SPRYSEC family of proteins from G. pallida show different subcellular localization patterns in plants, with some localized to the cytoplasm and others to the nucleus and nucleolus. Differences in subcellular localization may reflect diverse functional roles for each individual protein or, more likely, variety in the compartmentalization of plant proteins targeted by the nematode. Our data are therefore consistent with the suggestion that the SPRYSEC proteins suppress host defences, as suggested previously, and that they achieve this through interaction with a range of host targets.     

Development and use of anchored‐SSRs to study DNA polymorphism in bread wheat (Triticum aestivum L.)

In bread wheat, 21 anchored simple sequence repeat (SSR) primer pairs detecting SSR length polymorphism and 42 anchored SSR primers detecting microsatellite‐anchored fragment length polymorphisms (MFLPs) are reported. Eight bread wheat genotypes were used for detecting polymorphism. The number of alleles in SSR analysis ranged from two to six, with a mean of 2.9 alleles per SSR. The number of polymorphic bands in MFLP ranged from two to 40, with a mean of 12.74 polymorphic bands/primer combination, the SSRs with CT/GA motifs giving the highest level of polymorphism (a mean of 18.37 bands). The average value of polymorphic information content (PIC) was 0.473 for SSRs and 0.061 for MFLP.