Comparative study on the phenology, gender and yield components of cucumber (Cucumis sativus L.) varieties

The intensity of sex expression is important in crops, including cucumber, since sex form and flowering have direct effects on date of harvesting and yield. Two groups of cucumber comprising a native variety (Odukpani) and elite varieties (Griffaton, Poinsett, Ashley, Marketmore and Monarch) were evaluated in 2015 and 2016 cropping seasons at the Teaching and Research Farm, College of Agriculture, Garkawa, Plateau State; to assess flowering, sex expression and some yield traits. The experimental design was randomized complete block design with the 6 cucumber varieties as the treatments, replicated five times. The two groups differed significantly (p < 0.05) in phonological, flowering and yield traits assessed. The elite varieties were superior with respect to flowering traits, as they flowered early. The intra-population hierarchical cluster analysis of quantitative traits grouped the elite varieties in one main cluster and the native variety (Odukpani) alienated as an outlier. The cluster plots showed that Odukpani was robust in vegetative growth, produced few but larger fruit size and flowering was delayed for over two weeks. Conversely, the elite varieties flowered early, produced more flowers and recorded superior number of fruits per plant. The profuse production of pistillate flowers by the elite varieties had pronounced yield advantage over the local variety. Hybridization between the two groups of cucumber would make a mark in the drive for sustainable cucumber fruit yield.

Transcriptome analysis identifies candidate genes in the biosynthetic pathway of sex pheromones from a zygaenid moth, Achelura yunnanensis (Lepidoptera: Zygaenidae)

In most moth species, sex pheromones responsible for mating and communication of both sexes are primarily produced by the pheromone glands (PGs) of female moths. Although the PG transcriptomes and pheromone production related genes from 24 moth species have been characterized, studies on the related information remain unknown in the Zygaenidae family. Here, we sequenced the PG transcriptome of a zygaenid moth, Achelura yunnanensis. Such the sequencing resulted in the yields of 47,632,610 clean reads that were assembled into 54,297 unigenes, coupled with RNA sequencing data from 12 other tissues. Based on the transcriptome, a total of 191 genes encoding pheromone biosynthesis and degradation enzymes were identified, 161 of which were predicted to have full-length sequences. A comparative analysis among 24 moth species of nine families indicated that the numbers of the genes were variable, ranging from 14 in two Grapholita species to 191 in A. yunnanensis. Phylogenetic analysis in parallel with the expression data highlighted some key genes, including three △9 and four △11 desaturases, four fatty acyl-CoA reductases (FARs) clustering in the pgFAR clade, and three significantly antennae-enriched aldehyde oxidases. An extensive tissue- and sex- expression profile revealed a broad distribution of the genes, in which 128 relatives were detected in the PGs and 127 in the antennae. This study reports, for the first time, the gene repertoires associated with the pheromone production in Zygaenidae, and provides a valuable resource for exploring putative roles of the PG-enriched genes in A. yunnanensis.

Disentangling the effects of jasmonate and tissue loss on the sex allocation of an annual plant

Selection through pollinators plays a major role in the evolution of reproductive traits. However, herbivory can also induce changes in plant sexual expression and sexual systems, potentially influencing conditions governing transitions between sexual systems. Previous work has shown that herbivory has a strong effect on sex allocation in the wind-pollinated annual plant Mercurialis annua, likely mediated by resource loss. It is also known that many plants respond to herbivory by inducing signalling, and endogenous responses to it, via the plant hormone jasmonate. Here, we attempt to uncouple the effects of herbivory on sex allocation in M. annua through resource limitation (tissue loss) versus plant responses to jasmonate hormone signalling. We used a two-factorial experiment with four treatment combinations: control, herbivory (25% chronic tissue loss), jasmonate, and combined herbivory and jasmonate. We estimated the effects of tissue loss and defence-inducing hormones on reproductive allocation, male reproductive effort, and sex allocation. Tissue loss caused plants to reduce their male reproductive effort, resulting in changes in combined sex allocation. However, application of jasmonate after herbivory reversed its effect on male investment. Our results show that herbivory has consequences on plant sex expression and sex allocation, and that defence-related hormones such as jasmonate can buffer the impacts. We discuss the physiological mechanisms that might underpin the effects of herbivory on sex allocation, and their potential implications for the evolution of plant sexual systems.

Production of Feminized Seeds of High CBD Cannabis sativa L. by Manipulation of Sex Expression and Its Application to Breeding

The use of the cannabis plant as a source of therapeutic compounds is gaining great importance since restrictions on its growth and use are gradually reduced throughout the world. Intensification of medical (drug type) cannabis production stimulated breeding activities aimed at developing new, improved cultivars with precisely defined, and stable cannabinoid profiles. The effects of several exogenous substances, known to be involved in sex expressions, such as silver thiosulfate (STS), gibberellic acid (GA), and colloidal silver, were analyzed in this study. Various concentrations were tested within 23 different treatments on two high cannabidiol (CBD) breeding populations. Our results showed that spraying whole plants with STS once is more efficient than the application of STS on shoot tips while spraying plants with 0.01% GA and intensive cutting is ineffective in stimulating the production of male flowers. Additionally, spraying whole plants with colloidal silver was also shown to be effective in the induction of male flowers on female plants, since it produced up to 379 male flowers per plant. The viability and fertility of the induced male flowers were confirmed by fluorescein diacetate (FDA) staining of pollen grains, in vitro and in vivo germination tests of pollen, counting the number of seeds developed after hybridization, and evaluating germination rates of developed seeds. Finally, one established protocol was implemented for crossing selected female plants. The cannabinoid profile of the progeny was compared with the profile of the parental population and an improvement in the biochemical profile of the breeding population was confirmed. The progeny had a higher and more uniform total CBD (tCBD) to total tetrahydrocannabinol (tTHC) ratio (up to 29.6; average 21.33 ± 0.39) compared with the original population (up to 18.8; average 7.83 ± 1.03). This is the first comprehensive report on the induction of fertile male flowers on female plants from dioecious medical cannabis (Cannabis sativa L.).

Genetic variation in melon (Cucumis melo L.) landraces and wild relatives of Karnataka state of southern India

Melon (Cucumis melo L.) is an economically important vegetable crop worldwide. Karnataka state of southern India is rich in melon landraces and wild relatives, which are potential sources of genetic diversity for crop improvement. Here we report on the collection, characterization and documentation of previously unexplored landrace and wild material to broaden the availability of this genetic diversity for use in melon improvement. Accessions of botanical groups, momordica, kachri, chandalak, reticulatus, acidulus and indicus, intermediate forms of acidulus and momordica, and three melons of an unknown group were sourced directly from farmers of eight agro-ecological regions. Twenty-three representative melon landraces and wild relatives, along with four reference varieties of different botanical groups, were evaluated for agronomic traits during the year 2016. Very wide and distinctive genetic variations were observed among the melon accessions for ovary characters, sex expression, days taken to first fruit maturity, external and internal fruit traits, and fruit cracking (splitting). The remarkable variability displayed among the melon accessions as observed from the study demonstrates the importance of them as a valuable genetic reservoir for melon improvement.

Alterations in plasma hyaluronic acid in patients with clinically stable COPD versus (non)smoking controls

Hyaluronic acid (HA) is a key component of the extracellular matrix. HA and its metabolism are suggested to be altered in the lungs of patients with chronic obstructive pulmonary disease (COPD). The present study explored systemic HA, and its metabolic regulators, in patients with clinically stable COPD and smoking and non-smoking controls. Furthermore, associations of HA with acute exacerbations (AECOPD), airway-related hospitalizations, systemic inflammation and cardiovascular risk were studied. In total, 192 patients with moderate to very severe COPD [aged 62.3 y (± SD 7.0)], 84 smoking controls [aged 61.8 y (± 5.7)], and 107 non-smoking controls [aged 60.1 y (± 7.0)] were included. Plasma HA was reduced in patients with COPD compared to non-smoking controls (p = 0.033), but was comparable after adjusting for age and sex. Expression of HAS-3 did not differ between groups, but was substantially less detectable in more patients with COPD than (non)smoking controls (p < 0.001). Expression of HYAL-2 was enhanced in patients with COPD versus smoking (p = 0.019) and non-smoking (p < 0.001) controls, also in the age- and sex- adjusted model (p < 0.001). Plasma HA was not associated with AECOPD, airway-related hospitalizations in the previous year, or systemic inflammation in COPD. Arterial pulse wave velocity explained some of the variance (< 10%) in plasma HA (p = 0.006). Overall, these results indicate that expression of HYAL-2, but not plasma HA nor HAS-3, is enhanced in patients with COPD compared to (non)smoking controls. Furthermore, HA was not associated with clinical outcomes, yet, cardiovascular risk might play a role in its systemic regulation in stable COPD.

GENETIC RELATIONSHIPS AMONG PISTACIA VERA L. F1 HYBRIDS AND THEIR PARENTS (P. VERA×HERMAPHRODITE GENOTYPES OF P. ATLANTICA) USING SSR MARKERS

This research was conducted at the Scientific Agricultural Research center in Sweida province during (2014-2015). Breeding program was assessed in the aim to insert the bisexual phenomena of P.atlantica species (3 different hermaphrodite genotypes PA12, PA35, and PA37 as donators of pollen grains) to the commercial cultivars of P.vera (Ashouri and Batouri). Genetic relationships among the previous species and their progenies (F1, 6 genotypes of crossing program) was studied using 20 specific SSRs primer pairs, 16 of them were able to detect PCR amplification. Simple Sequence Repeat (SSR) segregation produced 44 putative alleles, out of which 40 were polymorphic (90.91%). Genetic similarity between the hybrids and their parents were closer to their female than to their male parents except for the hybrid HB3,which revealed a genetic distance 0.37 with its female parent (Batouri cultivar FB) and 0.43 with its male parent (PA35 hermaphrodite P.atlantica genotype). The UPGMA cluster plots based on Jaccard’s coefficient grouped the genotypes into two main clusters. The number of alleles revealed by each SSR analysis ranged from 1 to 8, with a level of expected heterozygosity (He) 0.496, observed heterozygosity (Ho) 0.25, and Marker Index (MI) 19.84. These results suggested the efficiency of SSR markers for distinguishing lineage genetic studies in the Pistacia spp. in breeding programs to elicit new cultivars, in particularly the primer pairs Ptms-7, EPVM021, EPVM016, and EPVF019 which may form the platform to detect sex expression in the genus Pistacia.

Gender plasticity uncovers multiple sexual morphs in natural populations of Cedrus deodara (Roxb.) G. Don

Background The expression of gender in gymnosperms is challenging because the extent of variability in gender segregations in tree crowns and selection pressure of nature can modify the gender through time. Methods An in-depth investigation on spatial segregation of genders in tree crowns and sex expression of a total of 500 trees in five different natural populations of Cedrus deodara was carried out and verified the occurrence of subdioecious (co-existence of male, female, and monoecious) genders in C. deodara. Results Five different sexual morphs were apparent among the 500 selected individuals as (1) pure male (M): bearing only male strobili in the whole crown with 22.2%; (2) pure female (F): bearing only female strobili in the whole crown with 12.4%; (3) mixed-monoecious (MM): bearing both male and female strobili with 13.6%; (4) predominantly female (PF) with 25.6%; and (5) predominantly male (PM) with 26.2%. The occurrence of multiple sexual morphs resulted from the complex selection pressure, which increased the stability of the populations. The segregation of genders in crown layers deemed to increase the fitness that may be a mechanism for accelerating outcrossing. The results of the study suggest that the subdioecious gender expression in C. deodara is evolved through the monoecy–paradioecy pathway. The production of male strobili revealed non-significant effect of tree sizes whereas a significant effect was observed for the production of female strobili. Our study established that the total pollen and seed outputs in C. deodara changed frequently according to gender expression. Conclusions The size of the tree, resource availability, sex allocation, plant architecture, gender segregation in crowns, and habitat conditions are the prominent causes for gender plasticity.

Epigenetics and microRNAs in UGT1As

UDP-glucuronosyltransferases (UGTs) are the main phase II drug-metabolizing enzymes mediating the most extensive glucuronidation-binding reaction in the human body. The UGT1A family is involved in more than half of glucuronidation reactions. However, significant differences exist in the distribution of UGT1As in vivo and the expression of UGT1As among individuals, and these differences are related to the occurrence of disease and differences in metabolism. In addition to genetic polymorphisms, there is now interest in the contribution of epigenetics and noncoding RNAs (especially miRNAs) to this differential change. Epigenetics regulates UGT1As pretranscriptionally through DNA methylation and histone modification, and miRNAs are considered the key mechanism of posttranscriptional regulation of UGT1As. Both epigenetic inheritance and miRNAs are involved in the differences in sex expression and in vivo distribution of UGT1As. Moreover, epigenetic changes early in life have been shown to affect gene expression throughout life. Here, we review and summarize the current regulatory role of epigenetics in the UGT1A family and discuss the relationship among epigenetics and UGT1A-related diseases and treatment, with references for future research.

Herbivory enhances leaky sex expression in the dioecious herb Mercurialis annua

Plant reproductive traits are widely understood to be responsive to the selective pressures exerted by pollinators, but there is also increasing evidence for an important role of antagonists such as herbivores in shaping these traits. Many dioecious species show leaky sex expression, with males and females occasionally producing flowers of the opposite sex. Here we show that leaky sex expression in both males and females of the wind-pollinated dioecious herb Mercurialis annua (Euphorbiaceae) is enhanced in response to simulated herbivory, increasing the probability and the degree of leakiness in both sexes. We also found that leakiness was greater in larger females but not in larger males. We discuss hypotheses for a possible functional link between herbivory and leaky sex expression, and consider what herbivory-induced leakiness might imply for the evolutionary ecology of plant reproductive systems, especially the breakdown of dioecy and the evolution of hermaphroditism.