Multiple seedlings in fluted pumpkin (Telfairia occidentalis hook. F.): Evidence for the occurrence of polyembryony

Investigations were conducted to identify types of seedlings occurring in Telfairia occidentalis (Hook F.). Attempts were made to trace their origins. Multiple embryos were observed to occur on the embryonic axis in separate and conjoined forms. A set of completely independent twins was found. Morphological differences between the primary shoot and the additional shoots from the same seed were not significantly different (P>0.05). Genetic studies revealed that all individuals originating from one seed were of the same sex, regardless of location. Chromosome number, 2n = 24 was recorded for all individuals of the separate and conjoined types and those arising from the cotyledons as well. The occurrence of separate seedling may be due to monozygotic cleavage of the embryo. Conjoined seedlings may have arisen as a result of post zygotic proliferation of the embryo. Origin of the independent twin seedlings is yet to be studied. Polyembryony was apparently post germinal in conjoined seedlings but suspected to be pre- germinal in the completely separate seedlings.Journal of Applied Chemistry and Agricultural Research Vol. 7 2000-2001: pp. 17-2

Variations in some morphological and yield characteristics of mungbean (Vigna radiata (L.) Wilczek) cultivars introduced into the rain-forest agroecology of Southeastern Nigeria

In an effort to increase the legume base of the people, mungbean (Vigna radiata (L) Wilczek) was introduced into the agro-ecology of southeastern Nigeria. During a field evaluation of mungbean cultivars at Michael Okpara University of Agriculture, Umudike, Nigeria, nine (9) plants were observed to differ in some vegetative and reproductive traits. The plants were consequently protected and their seeds harvested for further investigations. The progenies of the 9 genotypes and 2 mungbean cultivars (NM-92 and NM-94) were further evaluated in the screen house at the Federal University of Technology, Owerri, Nigeria. Data on the peduncle and vine lengths, days to 50 % anthesis, growth period, pod maturity period, pod length, number of seeds pod-1, number of pods plant-1 and 100 seed weight and subjected to analysis of variance using the unbalanced treatment procedure. In terms of the morphological characteristics, variation can be said to have occurred with regards to: growth habit (length of vine), vine hairiness, petal and seed coat colours. Results however show that Genotype-6 and Genotype-8 resemble the NM-92 and NM-94 cultivars in nearly all the attributes measured. Variations among the cultivars have also been observed in the aspects of: podyield per plant, pod and peduncle lengths, seed weight (g/100 seeds) and number of seeds per pod. Further studies are however ongoing to establish the genetic evidence of this phenotypic differences

Maize defence mechanisms against the European corn borer, Ostrinia nubilalis Hubner (Lepidoptera: Crambidae)

Maize is arguably the most widely grown crop in the world, but it is often associated with one of its major insect pests, the European corn borer (ECB). The damage caused by this species to maize production is generally variable, but in many cases it is economically significant. This review paper provides an overview of the research findings on the natural plant defence mechanisms against ECB larvae published till now. What is resistance and how it is achieved, what is the chemical response of maize plants to insect feeding and how tolerance can be increased. A short introduction in breeding for resistance and a discussion if the mentioned traits can be used in conventional breeding in order to create maize hybrids less affected by ECB are given