Mung bean (<Emphasis Type="Italic">Vigna radiata</Emphasis>) cultivars mediated oviposition preference and development of <Emphasis Type="Italic">Callosobruchus chinensis</Emphasis> (Coleoptera: Chrysomelidae: Bruchinae)

The Azuki bean weevil, Callosobruchus chinensis (L.), is a destructive pest of stored mung bean [Vigna radiata (L.) Wilczek] as well as other leguminous seeds. The development of resistant seeds to manage this pest is of current great interest to plant breeders. In this study, we investigated the oviposition preference and development of C. chinensis on two susceptible mung bean cultivars (Seonhwa and Gyeongseon) and one previously reported resistant cultivar (Jangan), compared to the susceptible cowpea (Vigna unguiculata L.), cultivar (Yeonbun) using both multiple-choice and no-choice tests. In addition, the development of C. chinensis was also examined at four constant temperatures (20, 25, 30, and 35 °C). Both tests found cowpea to be the most suitable seed for oviposition. Total developmental time from oviposition to adult emergence ranged from 27.01 to 38.2 days, being shortest on cowpea and longest on the mung bean, cv. Jangan. However, no successful development of C. chinensis larvae on mung bean, cv. Jangan, occurred at any temperature. The highest rate of adult emergence and the longest adult longevity both occurred on cowpea and certain mung bean cultivars (Seonhwa and Gyeongseon), with the dramatic exception of cv. Jangan. These results suggest that the higher preference and performance of C. chinensis on cowpea (3.3 egg/seed) and least on mung bean, cv. Jangan (0.4 egg/seed). This information may facilitate the exploration of resistant genetic materials and chemicals associated with seeds for successful breeding. Further studies should examine the chemicals associated with mung bean cultivars and its resistant mechanism to develop a control method against bruchines.     

Characterization of fragrance in sorghum (<Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.) Moench) grain and development of a gene-based marker for selection in breeding

Fragrance is one of the most important and valued quality characters in sorghum and other foods and attracts a premium price in local and global trade. The allele of the SbBADH2 gene in fragrant sorghum cultivar E228 was characterized. A 1441 bp deletion extending from exon 13 to 15 was found rather than a deletion from exon 12 to 15 as had been reported earlier. This allowed the development and validation of a new perfect PCR-based marker for identification of fragrant sorghum accessions in breeding. The concentration of 2-acetyl-1-pyrroline (2AP) in the grain of this cultivar was estimated to be 6.5 ± 0.4 ppb using headspace solid-phase microextraction (HS-SPME) coupled with GC-MS. Flavor components of fragrant sorghum accession E228 (IC 568489) were analyzed and compared with the non-fragrant M35-1 cultivar. PCA analysis revealed that 2AP, benzothiazole, 2,3,5-trimethylpyridine, (1E)-1-ethylidene-1H-indene, cedrene, 2,4-bis(2-methyl-2-propanyl)phenol, 2-hexyl-1-octanol, and 2-butyl-1-octanol were among 25 compounds that were found in sorghum grain that may be contributing toward the aroma of fragrant sorghum. Proline and methylglyoxal contents were found to be higher in E228 than in M35-1, while SbBADH2 expression in E228 was half that in M35-1, suggesting a similar 2AP biosynthetic mechanism to that found in fragrant rice and soybean.     

Improved Sprouting and Growth of Mung Plants in Chromate Contaminated Soils Treated with Marine Strains of <Emphasis Type="Italic">Staphylococcus</Emphasis> Species

Marine bacteria possess a wide variety of bioremediation potential which is beneficial environmentally and economically. In this study, bacterial isolates from marine waters were screened for tolerance and growth in high concentrations of chromate (Cr⁶⁺). Two isolates, capable of tolerating Cr⁶⁺ concentrations 300 µg mL^?1 or higher, and found to completely reduce 20 µg mL^?1 Cr⁶⁺ were grown in Cr⁶⁺ (50 and 100 mg kg^?1) spiked garden soil. Notably, both facilitated normal germination and growth of mung (Vigna radiata) seeds, which could hardly germinate in Cr⁶⁺ spiked garden soil without either of these bacteria. In fact, large percent of mung seeds failed to sprout in the Cr⁶⁺ spiked garden soil and could not grow any further. Apparently, chromate detoxification by marine bacterial isolates and the ability of mung plants to deal with the reduced form appear to work complementarily. This study provides an insight into marine bacterial abilities with respect to chromium and potential applications in promoting growth of leguminous plants-similar to mung in particular-in Cr⁶⁺ contaminated soil.     

<Emphasis Type="Italic">Rhizobium</Emphasis> strains in the biological control of the phytopathogenic fungi <Emphasis Type="Italic">Sclerotium</Emphasis> (<Emphasis Type="Italic">Athelia</Emphasis>) <Emphasis Type="Italic">rolfsii</Emphasis> on the common bean

Aims

To identify Rhizobium strains’ ability to biocontrol Sclerotium rolfsii, a fungus that causes serious damage to the common bean and other important crops, 78 previously isolated rhizobia from common bean were assessed.

Methods

Dual cultures, volatiles, indole-acetic acid (IAA), siderophore production and 16S rRNA sequencing were employed to select strains for pot and field experiments.

Results

Thirty-three antagonistic strains were detected in dual cultures, 16 of which were able to inhibit ≥84% fungus mycelial growth. Antagonistic strains produced up to 36.5 μg mL^?1 of IAA, and a direct correlation was verified between IAA production and mycelium inhibition. SEMIA 460 inhibited 45% of mycelial growth through volatile compounds. 16S rRNA sequences confirmed strains as Rhizobium species. In pot condition, common bean plants grown on S. rolfsii-infested soil and inoculated with SEMIA 4032, 4077, 4088, 4080, 4085, or 439 presented less or no disease symptoms. The most efficient strains under field conditions, SEMIA 439 and 4088, decreased disease incidence by 18.3 and 14.5% of the S. rolfsii-infested control.

Conclusions

Rhizobium strains could be strong antagonists towards S. rolfsii growth. SEMIA 4032, 4077, 4088, 4080, 4085, and 439 are effective in the biological control of the collar rot of the common bean.

     

Methane Yield and Feed Quality Parameters of Mixed Silages from Maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) and Common Bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.)

European agricultural policy increasingly focuses on environmental friendly cropping systems. Intercropping of maize (Zea mays L.) and common beans (Phaseolus vulgaris L.) has been suggested as an alternative cropping system with environmental benefits. The aim of this study was to assess methane yield potential of mixed silages. Based on material from two field experiments at three sites in Germany, mixed silages were produced with proportions of individual components varying from 0 to 100 % of fresh matter in increments of 12.5 %. Chemical parameters (neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (XP), starch, sugar, and crude fat) were determined, and batch tests were performed to measure methane yield potential from silages. With increasing bean proportion, concentrations of XP increased while NDF, methane yield, and methane content decreased. While methane yield showed a negative relationship with XP content (R ² = 0.56***), a positive relation was found with NDF (R ² = 0.55***). The reduction of methane yield of circa 1 L of methane per each additional bean percentage in the silages could not be explained by the chemical parameters of the silages. It is hypothesized that other chemical compounds, such as lectins, which were not determined in the present study, may have influenced methane production.     

Desiccation-induced ROS accumulation and lipid catabolism in recalcitrant <Emphasis Type="Italic">Madhuca latifolia</Emphasis> seeds

Loss of viability in desiccation-sensitive seeds of Madhuca latifolia (Roxb.) J. F. Macbr., an important multipurpose tropical tree, was correlated with seed water content (WC). WC declined from 0.59 to 0.19 g g^?1 fresh mass, 35 days after harvest from mother plant, at ambient conditions (temperature 25 ± 2 °C, relative humidity 50 ± 2%). The desiccation-induced reduction in viability was related with an accumulation of reactive oxygen species (ROS) that promoted lipid peroxidation associated loss of membrane integrity. Conducted study revealed 1.6–19 folds rise in lipid peroxidized products in desiccated M. latifolia seeds, and was found to be linked inversely with WC and germination percentage. Additionally, increased activities (7 and 13 folds) of lipid hydrolyzing enzymes; lipase (EC 3.1.1.3) and lipoxygenase (EC 1.13.11.12) respectively, were discernible in desiccating M. latifolia seeds. In summary, increased ROS, lipid oxidation, lipase and lipoxygenase were strongly correlated with viability loss in desiccating M. latifolia seeds.     

Behavioral responses of <Emphasis Type="Italic">Frankliniella occidentalis</Emphasis> to floral volatiles combined with different background visual cues

The Western flower thrips, Frankliniella occidentalis (Thysanoptera: Thripidae), is one of the most destructive sucking pests of flowering plants. We examined behavioral responses of F. occidentalis adults to the floral volatiles of Rosa chinensis, Gardenia jasminoides, and Tagetes erecta in a Y-tube olfactometer with background visual cues (green, red, white, yellow, and blue backgrounds). The results show that F. occidentalis adults had similar responses under all the different background colors, but the responses by sex varied significantly when offered floral volatile or clean air. In pairings of floral volatiles, female F. occidentalis adults presented significant preferences (R. chinensis > G. jasminoides > T. erecta) in each treatment, while male F. occidentalis adults had no significant preference. Furthermore, the responses of female F. occidentalis adults to the three different floral volatiles compared with each other were greater under green and blue backgrounds than red, white, or yellow backgrounds. However, the responses of male F. occidentalis adults to floral volatiles were similar to all five backgrounds. These results indicate that female thrips could discriminate different floral volatiles, while male thrips could not. Both male and female thrips performed steady preferences of floral volatiles under all the five visual backgrounds, and the behavioral responses of female thrips to the floral volatiles could be enhanced under the green and blue backgrounds. These findings could hopefully aid in the development of effective trapping and monitoring strategies for this pest.     

Exploring potential applications of a novel extracellular polymeric substance synthesizing bacterium (<Emphasis Type="Italic">Bacillus licheniformis</Emphasis>) isolated from gut contents of earthworm (<Emphasis Type="Italic">Metaphire posthuma</Emphasis>) in environmental remediation

The aim was to isolate, characterize, and explore potentials of gut bacteria from the earthworm (Metaphire posthuma) and imply these bacteria for remediation of Cu(II) and Zn(II). An extracellular polymeric substance (EPS) producing gut bacteria (Bacillus licheniformis strain KX657843) was isolated and identified based on 16S rRNA sequencing and phylogenetic analysis. The strain showed maximum tolerance of 8 and 6 mM for Cu(II) and Zn(II) respectively. It removed 34.5% of Cu(II) and 54.4% of Zn(II) at 25 mg L^?1 after 72 and 96 h incubation respectively. The bacteria possessed a great potential to produce indole acetic acid (38.49 μg mL^?1) at 5 mg mL^?1 l-tryptophan following 12 days incubation. The sterilized seeds of mung beans (Vigna radiata) displayed greater germination and growth under bacterium enriched condition. We observed that the bacterial strain phosphate solubilization ability with a maximum of 204.2 mg L^?1 in absence of Cu(II) and Zn(II). Endowed with biosurfactant property the bacterium exhibited 24% emulsification index. The bacterium offered significant potential of plant growth promotion, Cu(II) and Zn(II) removal, and as such this study is the first report on EPS producing B. licheniformis KX657843 from earthworm which can be applied as powerful tool in remediation programs of Cu(II) and Zn(II) contaminated sites.     

Conservation,ex vitro direct regeneration,and genetic uniformity assessment of alginate-encapsulated nodal cuttings of <Emphasis Type="Italic">Sphagneticola calendulacea</Emphasis> (L.) Pruski

A well-organized procedure was established for the conservation and distribution of Sphagneticola calendulacea (L.) Pruski [synonym Wedelia chinensis (Osbeck) Merrill] for the first time, using alginate-encapsulated nodal segments (NSs) as synthetic seeds. The ideal beads were obtained through a combination of 2.5% sodium alginate and 75 mM calcium chloride with 84.40 ± 2.20% rate of shoot emergence. The maximum regeneration (88.84 ± 2.24%) from synthetic seeds was achieved on liquid 1/2Murashige and Skoog (MS) medium in comparison to its other formulations. Furthermore, superior frequency (91.09 ± 2.24%) of complete plantlet (having both shoots and roots) formation was achieved when synthetic seeds were cultured on liquid 1/2MS (1.5% sucrose) fortified with 1.0 mg L^?1 N₆-benzyladenine plus 0.25 mg L^?1 α-naphthalene acetic acid. Synthetic seeds could be effectively stored at low temperature (8 °C) up to 90 days with a survival rate of 52.38 ± 3.06%, whereas higher temperature (25 °C) did not support regeneration after 75 days of storage. The plantlets were successfully acclimatized to natural conditions with ~ 89% survival frequency. To by-pass the time-consuming in vitro culture step after encapsulation, synthetic seeds were directly regrown into complete plantlets ex vitro on sand, soil, and vermicompost (1:1:1; w/w). Regeneration rate of 42.22 ± 2.22% was attained when NSs were pretreated on 1/2MS medium containing 4.0 mg L^?1 indole-3-acetic acid for 24 h in dark, prior to encapsulation. The random amplified polymorphic DNA and intersimple sequence repeat fingerprinting profiles demonstrated genetic uniformity amongst the regenerated plantlets, in vitro mother plant, as well as in vivo wild plant.     

Attraction to Host Plant Volatiles and Feeding Performance of <Emphasis Type="Italic">Naupactus Xanthographus</Emphasis> (Coleoptera: Curculionidae) is Affected by Starvation

The grape weevil, Naupactus xanthographus Germar (Coleoptera: Curculionidae), is a polyphagous insect which is a cause of important damage to several economically relevant crops, including grape (Vitis vinifera) and avocado (Persea americana), in several countries of Latin America. The larvae cause damage to the roots and rootlets of plants, and adults feed on leaves of their host plant. Despite its economic importance, there are few reports on the behavioral and nutritional ecology of this weevil. In this context, laboratory feeding and olfactometer bioassays with N. xanthographus were performed. The feeding performance was evaluated by measuring the weight variation of the insects after 1 and 6 h of feeding on grape or avocado leaves, respectively. After 1 h of feeding, insects showed no significant differences in weight increase. However, after a period of 6 h of feeding, males had continued feeding on grape leaves, but not on avocado leaves. Bioassays using a Y-tube olfactometer showed that males are attracted to volatiles of both host plants. Furthermore, starved males and females showed no preference to volatiles of grape or avocado. However, non-starved males and females preferred grape volatiles over avocado volatiles. Based on the combined results of the assays, we conclude that grape is preferred over avocado for N. xanthographus. Furthermore, this is the first report on the effect of starvation on the attraction to host plant volatiles in Curculionidae.     

Characterization of As(III) oxidizing <Emphasis Type="Italic">Achromobacter</Emphasis> sp. strain N2: effects on arsenic toxicity and translocation in rice

Achromobacter sp. strain N2 was isolated from a pyrite-cinder-contaminated soil and presented plant growth promoting traits (ACC deaminase activity, production of indole-3-acetic and jasmonic acids, siderophores secretion, and phosphate solubilization) and arsenic transformation abilities. Achromobacter sp. strain N2 was resistant to different metals and metalloids, including arsenate (100 mM) and arsenite (5 mM). The strain was resistant to ionic stressors (i.e., arsenate and NaCl), whereas bacterial growth was impaired by osmotic stress. Strain N2 was able to oxidize 1.0 mmol L^?1 of arsenite to arsenate in 72 h. This evidence was supported by the retrieval of an arsenite oxidase AioA gene highly homologous to arsenite oxidases of Achromobacter and Alcaligenes species. Rice seeds of Oryza sativa (var. Loto) were bio-primed with ACCD-induced and non-induced cells in order to evaluate the effect of inoculation on rice seedlings growth and arsenic uptake. The bacterization with ACCD-induced cells significantly improved seed germination and seedling heights if compared with the seeds inoculated with non-induced cells and non-primed seeds. Enhanced arsenic uptake was evidenced in the presence of ACCD-induced cells, suggesting a role of ACCD activity on the mitigation of the toxicity of arsenic accumulated by the plant. This kind of responses should be taken into account when proposing PGP strains for improving plant growth in arsenic-rich soils.     

High-efficient <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated <Emphasis Type="Italic">in planta</Emphasis> transformation in black gram (<Emphasis Type="Italic">Vigna mungo</Emphasis> (L.) Hepper)

In vitro culture and genetic transformation of black gram are difficult due to its recalcitrant nature. Establishment of gene transfer procedure is a prerequisite to develop transgenic plants of black gram in a shorter period. Therefore, genetic transformation was performed to optimize the factors influencing transformation efficiency through Agrobacterium tumefaciens-mediated in planta transformation using EHA 105 strain harbouring reporter gene, bar, and selectable marker, gfp-gus, in sprouted half-seed explants of black gram. Several parameters, such as co-cultivation, acetosyringone concentration, exposure time to sonication, and vacuum infiltration influencing in planta transformation, have been evaluated in this study. The half-seed explants when sonicated for 3 min and vacuum infiltered for 2 min at 100 mm of Hg in the presence of A. tumefaciens (pCAMBIA1304– bar) suspensions and incubated for 3 days co-cultivation in MS medium with 100 µM acetosyringone showed maximum transformation efficiency (46 %). The putative transformants were selected by inoculating co-cultivated seeds in BASTA^® (4 mg l^?1) containing MS medium followed by BASTA^® foliar spray on 15-day-old black gram plants (35 mg l^?1) in green house, and the transgene integration was confirmed by biochemical assay (GUS), Polymerase chain reaction, Dot-blot, and Southern hybridisation analyses.     

Purification and partial characterization of phytase from rice bean (<Emphasis Type="Italic">Vigna umbellata</Emphasis> Thunb.) germinated seeds

Rice bean (Vigna umbellata Thunb.) phytase activity increased during germination and reached maximum at 72 h. The phytate content in seeds decreased with increase in germination time. Phytase was purified 32 fold from 72-h germinated cotyledons with final specific activity 2.22 U/mg. Native PAGE revealed a single band. On SDS PAGE, it revealed two bands with molecular mass 66 and 44 kDa. The native molecular mass was 110 kDa on size exclusion chromatography. The A₂₈₀/₂₆₀ ratio was 1.88. When the enzyme was excited at 295 nm, the emission maximum was observed at 330 nm. The FTIR results suggest that Lys, Tyr, Phe, Trp, Ser, Gln and Asn residues on the enzyme’s surface. The enzyme was stored at 4 °C, showed 12 % residual activity on 35th day which was improved to 53.6 and 65.7 %, respectively in the presence of additives ascorbic acid and acetaminophen. The optimum pH and temperature of enzyme were 4.0 and 40 °C, respectively. The energy of activation was 32.2 kJ/mol. The values of K _m and V _max were 0.197 mM and 2.35 μmol/min/mg protein, respectively with sodium phytate as substrate. Phytase showed broad substrate specificity. The k _cat/K _m ratio was the highest for sodium phytate.     

Insecticidal activities of monoterpenes and phenylpropenes against <Emphasis Type="Italic">Sitophilus oryzae</Emphasis> and their inhibitory effects on acetylcholinesterase and adenosine triphosphatases

In the present study, six monoterpenes [(?)-citronellal, p-cymene, (?)-menthone, α-pinene, α-terpinene, and (?)-terpinen-4-ol] and two phenylpropenes [trans-cinnamaldehyde and eugenol] were evaluated for their contact and fumigant toxicities against Sitophilus oryzae adults. The effects of these compounds on the mortality of S. oryzae adults in stored wheat and their inhibitory effects on acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) were examined. The tested compounds showed varying degrees of contact toxicity, with trans-cinnamaldehyde (LC₅₀ = 0.01 mg/cm²) being the most potent compound, followed by (?)-menthone (LC₅₀ = 0.013 mg/cm²) and eugenol (LC₅₀ = 0.015 mg/cm²). In a fumigant toxicity assay, the monoterpenes α-terpinene, p-cymene, and (?)-menthone showed the highest toxicities (LC₅₀ = 50.79, 52.37, and 54.08 μl/L air, respectively). Trans-cinnamaldehyde, (?)-citronellal, and eugenol were the least toxic (LC₅₀ > 100 μl/L air). In general, the oxygenated compounds exhibited high contact toxicities while the hydrocarbon compounds exhibited high fumigant toxicities. When tested for their insecticidal activities against S. oryzae in stored wheat, trans-cinnamaldehyde was found to be the most potent compound, with 73.9% mortality at an application rate of 0.5 g/kg and complete mortality (100%) at 1 and 5 g/kg after 1 week of treatment. All of the tested compounds showed AChE inhibition, although (?)-citronellal and trans-cinnamaldehyde presented the strongest enzyme inhibition, with IC₅₀ values of 18.40 and 18.93 mM, respectively. On the other hand, (?)-terpinene-4-ol exhibited the highest inhibition of ATPases, followed by α-pinene and α-terpinene.     

Grain yield of common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) varieties is markedly increased by rhizobial inoculation and phosphorus application in Ethiopia

A field experiment was conducted to assess plant growth, symbiotic performance and grain yield of common bean in response to rhizobial incoculation and phosphorus application at Galalicha in Southern Ethiopia during the 2012 and 2013 cropping seasons under rain-fed conditions. The treatments consisted of 2 released common bean varieties (Hawassa Dume and Ibbado), 3 levels of Rhizobium inoculation (uninoculated, inoculated with strain HB-429 or GT-9) and 4 levels of phosphorus application (0, 10, 20 and 30 kg P ha^?1) using a split-split plot design with four replications. Here, phosphorus levels, Rhizobium inoculation and common bean varieties were assigned as main, sub- and sub-sub treatments, respectively. The results revealed marked varietal differences in plant growth, grain yield and symbiotic performance. Of the two common bean varieties studied, Hawassa Dume generally showed superior performance in most measured parameters in 2013. Rhizobium inoculation significantly (p?≤?0.05) increased plant growth, symbiotic performance and grain yield. Applying Rhizobium strain HB-429 to bean crop respectively increased plant growth, %Ndfa, amount of N-fixed and grain yield by 19, 17, 54 and 48% over uninoculated control. Similarly, the application of 20 kg P ha^?1 to bean plants respectively resulted in 36, 20, 96 and 143% increase in plant growth, %Ndfa, N-fixed and grain yield when compared to the control. These results clearly indicate that plant growth, symbiotic performance and grain yield of common bean can be significantly increased by Rhizobium inoculation and phosphorus fertilization in Ethiopia. Rhizobium inoculants are a cheaper source of nitrogen than chemical fertilizers and when combined with moderate phosphorus application can markedly increase grain yield for resource-poor farmers.     

Association mapping of days to flowering in common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.) revealed by DArT markers

In the current study, 173 common bean genotypes from several geographic regions were studied. Days to flowering (DF) was evaluated in two experimental locations in Izmir, Turkey (Bornova and Menemen) in 2 years (2015 and 2016) and was found to range from 30 to 62.7 days with a mean value of 41.5 days. A total of 22,848 SNPs based on diversity array technology were developed, and after filtering, the remaining 20,766 SNP markers were used for calculating linkage disequilibrium. Chromosomes 1–11 contained 1846, 2342, 2184, 1153, 1351, 1520, 1953, 2080, 2065, 1199, and 1511 SNPs, respectively. A total of 1562 SNPs were identified as scaffold markers. The PIC value was 0.25, ranging from 0.005 to 0.500. Common bean accessions were divided into two main subpopulations, namely POP1 (Mesoamerican) and POP2 (Andean). Mixed linear model using the Q + K model showed that three SNPs had a significant association (p?<?0.01) in Bornova in 2015 and seven SNPs had a significant association (p?<?0.01) in the same location in 2016. Five significant associations (p?<?0.01) were identified in 2015 while six (p?<?0.01) were identified in Menemen in 2016. When the data from both locations and both years was combined, six SNPs were significant (p?<?0.01). For DF, 11 putative candidate genes were predicted from the sequences representing homology to linked SNPs. We conclude that the markers, which were significantly associated with the DF of the common bean genotypes in the current study, can be used for marker-assisted selection in plant breeding program of common bean.     

Unraveling the inheritance pattern of yield and associated traits in Rapeseed (<Emphasis Type="Italic">Brassica napus</Emphasis> L.)

In this study, 56 F₁ crosses of B. napus, including their eight parents, were developed through complete diallel mating design. Analysis of variances (ANOVA) of combining ability showed very highly significant (P ≤ 0.01) values for the general combining (GCA), specific combining (SCA) and the reciprocal combining ability (RCA) towards yield and its associated traits. Parental lines, AUP-9 (3.51), AUP-18 (37.26), AUP-20 (0.12), AUP-7 (0.11), and AUP-18 (5.66), were found as the best general combiners for each of the traits: pods on main raceme, pods on individual plant, seeds on each pod, 1000 seed weight and seed yield plant^?1, respectively, whereas, based on desirable SCA effects, crosses found best were AUP-14 × AUP-18, AUP-14 × AUP-20, AUP-8 × AUP-20, AUP-2 × AUP-18, AUP-2 × AUP-14, and AUP-2 × AUP-9 for pods main raceme^?1, pods plant^?1, seeds pod^?1, 1000 seed weight and seed yield plant^?1, respectively. Superior reciprocal hybrids for economically important traits such as pods main raceme^?1, pods plant^?1, seeds pod^?1, and seed yield plant^?1 were AUP-17 × AUP-9, AUP-14 × AUP-2, AUP-18 × AUP-7 and AUP-20 × AUP-8, respectively, involving at least one best general combiner (parental line). Estimates of combining ability variances and predictability ratio (σ ²GCA/σ ²SCA <1.00) revealed the preponderance of a non-additive gene action and was further confirmed by higher values of variances due to SCA than GCA.     

<Emphasis Type="Italic">In vitro</Emphasis> regeneration,production, and storage of artificial seeds in <Emphasis Type="Italic">Ceropegia barnesii</Emphasis>, an endangered plant

Approaches for in vitro regeneration and fabrication of synthetic seeds were formulated to support restoration in the wild and genetic manipulation of Ceropegia barnesii (categorized as endemic and endangered). MS medium augmented with 4 mg L^?1 benzyl adenine was most advantageous for the production of multiple shoots from nodal explants. Fabrication of synthetic seeds was accomplished by sodium alginate encapsulation of nodes from microshoots. The most favorable medium combination for the induction of multiple shoots from synthetic seeds was MS medium complemented with 4 mg L^?1 benzyl adenine and 1 mg L^?1 gibberelic acid. Following root induction promoted by half strength MS basal medium augmented with indolebutyric acid, multiple shoots were subjected to hardening. Influence of vesicular-arbuscular mycorrhizal fungi on the hardening trials was investigated and it was observed that dual inoculation of Glomus aggregatum and G. intraradices enhanced the survival rate. The encapsulated nodes of C. barnesii were tested for their capability to endure different temperatures during storage and the optimal temperature for storage was found to be 4°C. A methodology for initiation of somatic embryogenesis from C. barnesii is also reported here, but embryos could not be induced to develop further. The micropropagated plants were reintroduced in to their natural habitat. This is the first report on micropropagation of C. barnesii.     

Responses of the ambrosia beetle <Emphasis Type="Italic">Xylosandrus compactus</Emphasis> (Coleoptera: Curculionidea: Scolytinae) to volatile constituents of its symbiotic fungus <Emphasis Type="Italic">Fusarium solani</Emphasis> (Hypocreales: Nectriaceae)

Xylosandrus compactus is a polyphagus pest that cultivates a symbiotic fungus Fusarium solani in tunnels of host plants for food and is a major threat to coffee production in East Africa. We hypothesized that the female X. compactus, which is the only sex capable of flying to attack its hosts, is attracted to volatiles from F. solani. We investigated responses of females to volatiles released by fungal cultures and bioactive components identified in the fungal volatiles. In Y-tube olfactometer assays, ~68% of females were attracted to volatiles emitted from F. solani over clean air. Bioactive compounds were identified in the fungal volatiles by coupled gas chromatography (GC)/electroantennographic detection (EAD) and GC/mass spectrometric analyses as methyl isovalerate and 2,3-butanediol. We also identified ethanol, a known attractant of X. compactus, using solid phase microextraction captured fungal volatiles analyzed by GC/MS. In field trapping trials, we compared captures of females in plastic bottle traps baited with a range of doses of methyl isovalerate, 2,3-butanediol, and blends of the two compounds, with similar traps baited with solvent only and ethanol. Females were caught by all the baited traps at all the concentrations tested except traps baited with solvent only. Trap captures were however 14–37-fold lower in traps baited with single components and the blends than those baited with ethanol. The possible use of these components as a tool for kairomonal monitoring of populations of X. compactus is discussed.