Manipulation of in vivo pollination techniques to improve the fertilization efficiency of interspecies crosses in the genus Phaseolus

Phaseolus angustissimus A. Gray contains genes for traits of interest for dry bean (P. vulgaris) breeders. F₁ hybrids can be produced but introgression through backcrossing has been a problem. One of the main impediments is the time required between pollination and fertilization when F₁ hybrids of P. vulgaris/P. angustissimus are backcrossed with P. vulgaris. In an attempt to reduce this time, the effect of alternative pollination techniques was studied. The rate and the time of fertilization were ascertained using three different pollen types (pollen germinated in vitro, fresh pollen (FP) mixed in pollen‐germinating media and FP), and two methods of pollination (cut‐style and stigmatic pollinations). An optimal in vitro pollen germination medium for Phaseolus pollen was developed. Low temperatures (6–9°C) were demonstrated to be necessary for Phaseolus pollen germination. Pollination using a cut‐style technique coupled with pregerminated pollen reduced the time for fertilization in the backcrosses of interspecies hybrids by approximately 28 h. This technique improved the success rate of fertilization in wide crosses of Phaseolus designed to introgress genes from wild relatives.     

Comparison of Cadmium Ion Adsorption on Various ACTIVATED CARBONS

Studies on the removal of cadmium(II) ions from aqueous solutions by adsorption on various activated carbons [commercial activated carbon (CAC) and chemically prepared activated carbons (CPACs) from raw materials such as straw, saw dust and datesnut] have been carried out with an aim to obtain information on treating effluents containing Cd(II) ions. Factors influencing the adsorption of Cd(II) ions from aqueous solution by ACs have been investigated by following a batch adsorption technique at 30± 1 ^°C. The percentage removal increased with decrease in initial concentration and particle size of CPACs and an increase in contact time, dose and initial pH of the solution. Adsorption process was inhibited by the added electrolytes. The adsorption data were fitted with the Langmuir, Dubinim–Radushkevich and Freundlich isotherms and first-order kinetic equations viz., first-order, Lagergren and Bhattacharya–Venkobachar equations and intra-particle diffusion model. The kinetics of adsorption is first order with intra-particle diffusion as one of the rate determining steps. Thermodynamic parameters were obtained from equilibrium constants measured at 30, 35 and 40 ^°C (Error = ± 1 ^°C). Results of the studies on adsorption of Cd²⁺ ions from simulated wastewater were compared with that of CAC and Tulsion CXO-9(H), a commercial ion exchange resin/cationic resin (CR). Straw carbon showed the maximum adsorption capacity towards Cd²⁺ ions and a high value of rate constant of adsorption. Straw carbon is an alternative low-cost adsorbent to CAC.     

Improving RNA interference in the southern green stink bug,Nezara viridula

Journal of Pest Science - The southern green stink bug, Nezara viridula, is a worldwide pest of many important crops. RNA from N. viridula nymphs and adults was sequenced and assembled into a...