Estimates of Heritability and Genetic Advance for Yield Components of Cowpea (Vigna unguiculata L. Walp) under Drought Stress Conditions

The study was conducted at the Teaching and Research Farms, Federal University of Agriculture, Makurdi, Nigeria. Five Cowpea genotypes (FUAMPEA-1, IT99K-573-1-1, SAMPEA-16, SAMPEA-8, BIU LOCAL) were crossed and advanced to F1, F2, BC1 and BC2 populations using bi-parental mating design. The six generations were evaluated in a Randomized Complete Block Design with three replications. Significant test of the mean performances among the entries showed significant differences among the generations for the characters studied. Wide ranges of narrow sense heritability (18 to 79%), broad sense heritability (21 to 92%) and genetic advance (5.7 to 24.1%) were obtained for characters studied. Broad and narrow sense heritability as well as genetic advance was moderate to high for most of the characters studied such as days to 50% flowering, plant height, days to pod maturity, number of seeds per pod, number of pods per plant, hundred seed weight, root length and grain yield for the three sets of cowpea crosses. The results also revealed the possibility of exploitation for grain yield and drought tolerance in the crosses studied.

Impact of Bi-Parental Mating on Character Association in Barley (Hordeum vulgare L.)

Correlation between grain yield and contributing characters in 100 biparental progenies (BIPs) developed from a barley cross RD-2035 x RD-2552 and corresponding F3 progenies were compared. The correlation coefficients in BIPs were found generally of higher magnitude than F3 progenies. Even, non-significant negative association in F3 between grain yield per plant and harvest index converted into significant and positive in BIP progenies. Higher degree of positive and significant correlation was observed in tillers per plant, spikelets per spike and grain per spike with grain yield per plant in BIPs as well as F3 population.

Biology of Mushroom Phorid Flies, Megaselia halterata (Diptera: Phoridae): Effects of Temperature, Humidity, Crowding, and Compost Stage

The mushroom phorid fly, Megaselia halterata (Wood), is a common pest of mushroom production in many parts of the world. Due to the reduced availability of conventional insecticides for mushroom production, M. halterata has recently developed into a major pest in the top mushroom-producing county in the United States (Chester County, PA). Mushrooms are grown entirely indoors, and though larval development of M. halterata occurs in the mushroom-growing substrate, adult flies have been captured both inside and outside of the facilities. Here, we investigated three factors that might contribute to their growth and development. 1) The effects of ambient temperature (15–30°C) and relative humidity (RH; 21–98%) on adult M. halterata lifespan, 2) the effect of spawned compost stage (freshly inoculated with spawn vs 14-d spawned compost) on reproductive output, and 3) the effect of population density on reproductive output. The longevity of adult M. halterata increased under cooler temperatures and more humid conditions (>75% RH), which reflect the conditions inside mushroom-growing facilities. Similar numbers of flies emerged from freshly inoculated and 14-d spawned compost, but flies emerged earlier from 14-d spawned compost. The higher the parental fly density, the more offspring emerged from spawned compost, but the positive relationship reached a plateau beyond 40 parental mating pairs per 100 g of compost. Our findings highlight relevant abiotic and biotic factors that may contribute to M. halterata population dynamics.

Sex, Age, and Parental Harmonic Convergence Behavior Affect the Immune Performance of Aedes aegypti Offspring

Aedes aegypti is an important vector of several pathogenic arboviruses including dengue, chikungunya and Zika. Innovative approaches to control Aedes populations, involving synthetic transgenic modifications as well as Wolbachia bacteria, appear promising. For the various techniques requiring offspring inheritance of a trait, released males must successfully compete for mating partners against wildtype males. However, very little is known about mechanisms of mate selection in mosquitoes in general and in particular about potential correlations between mating success and offspring immune performance.Harmonic convergence signals have been proposed as a cue for females to predict male quality. We investigated whether offspring of converging parental pairs showed differences in immune competence compared to offspring derived from non-converging parental pairs using three different types of immune assays. We found that offspring immune responses (melanization response and response to a bacterial challenge) differed between offspring from converging and non-converging parents. However, immune responses were shaped by several interacting factors such as sex, age, reproductive status, and parental mating behavior. Parental mating behavior had a stronger effect on the immune response of male offspring than on female offspring. Further, a population of female offspring derived from converging parental pairs reached their peak dengue virus dissemination rate earlier compared to a population of offspring derived from non-converging parental pairs. Our results provide insight into a wide range of selective pressures shaping mosquito immune function. Evolutionary trade-offs between naturally and sexually selected traits can have important implications for disease transmission and control and should be considered in the development of reproductive control strategies.

Preservation of Genetic Variation in a Breeding Population for Long-Term Genetic Gain

Genomic selection has been successfully implemented in plant and animal breeding. The transition of parental selection based on phenotypic characteristics to genomic selection (GS) has reduced breeding time and cost while accelerating the rate of genetic progression. Although breeding methods have been adapted to include genomic selection, parental selection often involves truncation selection, selecting the individuals with the highest genomic estimated breeding values (GEBVs) in the hope that favorable properties will be passed to their offspring. This ensures genetic progression and delivers offspring with high genetic values. However, several favorable quantitative trait loci (QTL) alleles risk being eliminated from the breeding population during breeding. We show that this could reduce the mean genetic value that the breeding population could reach in the long term with up to 40%. In this paper, by means of a simulation study, we propose a new method for parental mating that is able to preserve the genetic variation in the breeding population, preventing premature convergence of the genetic values to a local optimum, thus maximizing the genetic values in the long term. We do not only prevent the fixation of several unfavorable QTL alleles, but also demonstrate that the genetic values can be increased by up to 15 percentage points compared with truncation selection.

Measuring the Costs of Limb Regeneration and Their Transgenerational Consequences in Two Nearctic Lady Beetles (Coleoptera: Coccinellidae)

We examined the ability of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville to regenerate, during pupation, a foreleg amputated in the fourth instar. Leg regeneration was complete for 80.7% of amputated H. convergens larvae, with 12.5% regenerating partially, and 6.8% showing no regeneration. Regeneration in C. maculata was 72.2% complete, 20.5% partial, and 7.2% none, but mortality following ablation was slightly higher than for H. convergens (7.4 vs. 0.6%). Ablation/regeneration caused a slight delay in pupation, but pupation time, fresh mass at emergence, and reproductive performance remained unaffected in either species. Reciprocal crosses were made between regenerated and unoperated beetles, and 12 progeny reared from the second clutch of each female in all treatments. Mating treatment affected eclosion time in H. convergens, whereas in C. maculata, larval development and pupation time were also affected. Considering all treatments, larval mortality was higher in H. convergens than in C. maculata, but lower when both H. convergens parents regenerated. Parental mating treatment did not affect adult weight in either species, but development of C. maculata progeny was faster when only the sire regenerated, and slower when the only the dame regenerated, whereas progeny of regenerated sires completed pupated faster than those sired by controls. We infer that genes activated during regeneration have pleiotropic effects with subtle, gender-specific, epigenetic consequences. If these pleiotropic effects are genetically linked to important traits, regenerative genetic elements could be conserved in coccinellids via natural selection acting on these traits, rather than on regenerative ability per se.

Genetic analysis for yield and yield attributes in greengram (Vigna radiata L. Wilczek)

Six basic generations viz., P1, P2, F1, F2, B1 and B2 of five selected crosses viz., LGG-460 × WGG-37, TM-96-2 × WGG-37, TM-96-2 × PM-112, MGG-295 × PM-110 and MGG-351 × PM-115 were studied to assess the nature and mode of gene action for yield and its component traits through generation mean analysis. In general, magnitude of dominance effects (h) has greater value than additive effects (d) for majority of the traits in all the crosses. All the traits are under the influence of duplicate epistasis besides additive type of gene effects for which bi-parental mating or inter-se mating may be adopted followed by pedigree method of selection to modify the genetic architecture of greengram for attaining higher yields with desirable properties.

BINARY VECTOR CONSTRUCTION OF KAPPA(κ)-CARRAGEENASE GENE AND TRANSFORMATION TO Agrobacterium tumefaciens AS MEDIATOR FOR SEAWEED TRANSGENIC GENERATION

<p class="Default"><em>Increasing of kappa (κ)-carrageenan content in <span style="text-decoration: underline;">Kappaphycus</span> <span style="text-decoration: underline;">alvarezii</span> seaweed is potentially be achieved by applying transgenesis technology. </em><em>This study was performed to obtain a construction of κ-Carrageenase </em><em>gene and </em><em><span style="text-decoration: underline;">A</span></em><em><span style="text-decoration: underline;">grobacterium</span></em><em> </em><em><span style="text-decoration: underline;">tumefaciens</span></em><em> to carry those construction genes. The κ-Carrageenase (κ-Car) gene was </em><em>involved in κ-carrageenan biosynthesis. </em><em>The κ-Car gene sequence was ligated between the 35S CaMV promoter and tNos terminator sequences to generate pMSH/κ-Car expression vector. </em><em>Transformation of pMSH/κ-Car </em><em>plasmid</em><em> to <span style="text-decoration: underline;">Escherichia</span> <span style="text-decoration: underline;">coli</span> was performed by heat-shock </em><em>method, </em><em>and to <span style="text-decoration: underline;">Agrobacterium</span> <span style="text-decoration: underline;">tumefaciens</span> by tri-parental mating </em><em>method.</em><em> The results showed that several colonies of <span style="text-decoration: underline;">E</span>. <span style="text-decoration: underline;">coli</span> and <span style="text-decoration: underline;">A</span>. <span style="text-decoration: underline;">tumefaciens</span> grew in the selective culture </em><em>mediums containing antibiotic</em><em>. </em><em>PCR analysis using primers 35S-Forward and </em><em>tNos</em><em>-Reverse with DNA template from those bacterial colonies resulted DNA fragment of about 2,000 bp, the same as the total length of 35S CaMV promoter, κ-Car gene and tNos terminator </em><em>sequences. </em><em>Therefore, the construction of pMSH/κ-Car gene was </em><em>succeeded</em><em> and a colony of <span style="text-decoration: underline;">A</span>. <span style="text-decoration: underline;">tumefaciens</span> transformant carrying pMSH/κ-Car </em><em>plasmid</em><em> was successfully produced.</em></p><p><strong><em> Keywords: </em></strong><em><span style="text-decoration: underline;">A</span></em><em><span style="text-decoration: underline;">grobacterium</span></em><em> </em><em><span style="text-decoration: underline;">tumefaciens</span></em><em>, k</em><em>appa</em><em>(</em><em>κ</em><em>)</em><em>-Carrage</em><em>e</em><em>nase gene</em><em>, t</em><em>ransgenesis</em><em>, vector</em></p>

BINARY VECTOR CONSTRUCTION OF KAPPA(κ)-CARRAGEENASE GENE AND TRANSFORMATION TO Agrobacterium tumefaciens AS MEDIATOR FOR SEAWEED TRANSGENIC GENERATION

Increasing of kappa (κ)-carrageenan content in Kappaphycus alvarezii seaweed is potentially be achieved by applying transgenesis technology. This study was performed to obtain a construction of κ-Carrageenase gene and Agrobacterium tumefaciens to carry those construction genes. The κ-Carrageenase (κ-Car) gene was involved in κ-carrageenan biosynthesis. The κ-Car gene sequence was ligated between the 35S CaMV promoter and tNos terminator sequences to generate pMSH/κ-Car expression vector. Transformation of pMSH/κ-Car plasmid to Escherichia coli was performed by heat-shock method, and to Agrobacterium tumefaciens by tri-parental mating method. The results showed that several colonies of E. coli and A. tumefaciens grew in the selective culture mediums containing antibiotic. PCR analysis using primers 35S-Forward and tNos-Reverse with DNA template from those bacterial colonies resulted DNA fragment of about 2,000 bp, the same as the total length of 35S CaMV promoter, κ-Car gene and tNos terminator sequences. Therefore, the construction of pMSH/κ-Car gene was succeeded and a colony of A. tumefaciens transformant carrying pMSH/κ-Car plasmid was successfully produced. Keywords: Agrobacterium tumefaciens, kappa(κ)-Carrageenase gene, transgenesis, vector