PREMISE OF THE STUDY Distinguishing the contributions of phenotypic plasticity vs. population differentiation to variation in the life history of plants throughout their range is important for predicting their performance after dispersal or their responses to environmental change. In Erysimum capitatum, plants in alpine environments are iteroparous perennials, but those below tree line are seme...

The aim of this study was to identify periods in zebrafish (Danio rerio) development when estrogen exposure has long-term consequences on reproductive capabilities at the adult stage. To this end, zebrafish were exposed to 10 ng/L ethynylestradiol (EE(2)) during three stages of gonadal differentiation: (i) the juvenile hermaphroditic stage when gonads display the morphology of an immature ovary...

The sterile insect technique (SIT) involves the inundative release of irradiated (sterile or partially sterile) insects to decrease population levels in a target pest species. The effectiveness of SIT programs depends on sterile males mating successfully and inducing reproductive failure in wild females, or in the F1 generation in the case of lepidopteran species. Thus, from the perspective of ...

In the Sahel zone of West Africa that extends from Senegal to Chad, temperatures can vary from less than 15 ̋C to 25 ̋C from November to February. These low temperatures affect the growth, development and yield of rice plants, and therefore constitute a major constraint to rice production in the Sahel. In order to identify rice varieties tolerant to cold stress at different developmental stages...

Spodoptera frugiperda J.E. Smith (fall armyworm) is considered one of the most destructive pests of corn throughout the Americas. Although this pest has been extensively studied, little is known about its larval movement and feeding behavior on reproductive compared to vegetative corn stages. Thus, we conducted studies with two corn stages (R1 and R3) and four corn plant zones (tassel, above ea...

Animals that have a long pre-reproductive adult stage often employ mechanisms that minimize aging over this period in order to preserve reproductive lifespan. In a remarkable exception, one tephritid fruit fly exhibits substantial pre-reproductive aging but then mitigates this aging during a diet-dependent transition to the reproductive stage, after which life expectancy matches that of newly e...

Plasticity of the phenotypic architecture of wild barley, Hordeum spontaneum, was studied in response to water and nutrient stress. Direct and indirect selection on several vegetative and reproductive traits was estimated and path analysis used to reveal how regulating pathways via maternal investment differed between environments. Vegetative traits displayed differential regulating effect on f...

blast disease of rice caused by pyricularia oryzae is a potentially damaging disease in northern due to planting of susceptible local cultivars and favorable conditions. to assess the effects of blast on rice yield components and yield loss, one field experiment was conducted at the lowland culture conditions. analysis of blast effects on rice indicated that the maximum yield losses due to unpr...