Extracts of Euphorbia nivulia Buch.-Ham. showed both phytotoxic and insecticidal capacities against Lemna minor L. and Oxycarenus hyalinipennis Costa.

Many phytochemicals can affect the growth and development of plants and insects which can be used as biological control agents. In this study, different concentrations of crude, hexane, chloroform, butanol, and aqueous extracts of Euphorbia nivulia Buch.-Ham., an endemic plant of the Cholistan desert in South Punjab of Pakistan, were analysed for their chemical constituents. Their various concentrations were also tested for their phytotoxic and insecticidal potential against duckweed, Lemna minor L., and the dusky cotton bug, Oxycarenus hyalinipennis Costa. various polyphenols, i.e., quercetin, gallic acid, caffeic acid, syringic acid, coumaric acid, ferulic acid, and cinnamic acid were detected in different concentrations with different solvents during the phytochemical screening of E. nivulia. In the phytotoxicity test, except for 100 µg/mL of the butanol extract gave 4.5% growth regulation, no phytotoxic lethality could be found at 10 and 100 µg/mL of all the extracts. The highest concentration, 1000 µg/mL, of the chloroform, crude, and butanol extracts showed 100, 63.1, and 27.1% of growth inhibition in duckweed, respectively. In the insecticidal bioassay, the highest O. hyalinipennis mortalities (87 and 75%) were recorded at 15% concentration of the chloroform and butanol extracts of E. nivulia. In contrast, the lower concentrations of the E. nivulia extracts caused the lower mortalities. Altogether, these findings revealed that E. nivulia chloroform extracts showed significant phytotoxicity while all the extracts showed insecticidal potential. This potential can be, further, refined to be developed for bio-control agents.

Report: Pharmacognostic and physicochemical screening of Euphorbia nivulia Buch.-Ham.

Euphorbia nivulia Buch.-Ham. (Euphorbiaceae) is commonly known as Indian Spurge Tree in English, and "Saj Thor" or "Jhanami booti" in local language. The plant is used traditionally in the treatment of various diseases like inflammation, fever, worm infection, asthma, cough, wounds and diabetes. In current study fresh as well as dried aerial parts of the plant and cut sections were examined, both macroscopically and microscopically. The study also deals with fluorescence analysis and phytochemical characteristics and other WHO recommended methods for standardization. WHO guidelines on quality control for medicinal plants materials were used for pharmacognostical evaluation of E. nivulia, phytochemical screening helps in determining the predominant classes of active constituents responsible for the activity. The present work will be helpful in identification of the fresh and dried samples of aerial parts pharmacognostically and anatomically. These studies will serve as a reference for correct identification and may be helpful in checking any type of adulteration. These observations will also help in differentiating this species from closely related species of the same genus and family.

Dichogamy and sexual dimorphism in floral traits in the andromonoecious Euphorbia boetica.

BACKGROUND AND AIMS: Euphorbia boetica (Euphorbiaceae) is a functional andromonoecious species that shows both intra- and interfloral dichogamy, hermaphrodite cyathia being protogynous. Sexual dimorphism of the cyathia of E. boetica is examined according to their gender and arrangement on the inflorescence. METHODS: Data were obtained from two natural populations, where the distribution of male and hermaphrodite cyathia in the inflorescence was recorded. The size, pollen production and viability, and nectar secretion were measured in both types of cyathia. KEY RESULTS: Most cyathia were male at the first levels of the inflorescence, then hermaphrodite cyathia predominated at the successive levels, although at the last levels the proportion of male cyathia increased. Male cyathia at basal positions lack ovaries, whereas those at distal positions showed vestigial ovaries. The size of the cyathia varied significantly depending on the level of the inflorescence where they were produced: those of the last levels were usually smaller. The hermaphrodites were significant bigger than males; however, these differences were due to the differential distribution of each cyathium type in the inflorescence. Male cyathia produced significantly more pollen and nectar than hermaphrodites. CONCLUSIONS: In Euphorbia boetica, basal male cyathia could be explained by the presence of protogyny, and apical male cyathia seem to respond to a preemption of resources. A true dimorphism affecting primary sexual characters and related to gender function appears at lower levels of the inflorescence, whereas an apparent size dimorphism due to positional effects occurs at upper positions. Longevity and distribution of cyathia, and their pattern of nectar production, could improve both male and female fitness.

Functional andromonoecy in Euphorbia (Euphorbiaceae).

The occurrence of cyathia containing staminate flowers but lacking a pistillate flower was studied in 17 species of Euphorbia. Male cyathia were found in the majority of species studied (88.2%) giving functional andromonoecy. In the male cyathia, the pistillate flower is generally totally absent, but sometimes a vestigial pistillate flower with a non-functional ovary is present. The proportion of male cyathia varied at both the population and species level. The position of male cyathia within the inflorescence showed a constant pattern among species: the proportion of male cyathia decreased from the first to the last levels of the pleiochasia. In general, perennial species had significantly higher proportions of male cyathia than annual species (mean 20 and 2.3%, respectively). In annual species there was a trend for production of male cyathia only in the first level of the inflorescence, whereas in perennials production up to the fourth level of the inflorescence was usual. Functional andromonoecy is common in Euphorbia and represents a new sex segregation in the genus. The selective forces causing this secondary sex segregation in Euphorbia, such as improved pollination or increased outcrossing, are discussed.