Generative and Vegetative Traits of the 'Granny Smith' Apple Grown under an Anti-Insect Photoselective Red Net

Anti-insect photoselective nets present a new technology that combines light manipulation and pest protection in orchards. In this study, the effect of the anti-insect photoselective red net on the generative and vegetative traits was studied in an apple orchard near the city of Zadar, Croatia. 'Granny Smith' apples were grown on M9 rootstock and raised as slender spindles. The experiment consisted of two treatments: the trees covered with the red photoselective anti-insect nets (AGRITECH S. r. l., Eboli, Italy; mesh size of 2.4 × 4.8 mm) and uncovered trees as control. Yield, percentage of fruit with diameter >70 mm and fruit mass were not significantly different between treatments. L* color value was higher on fruit skin grown under the red net, and there was no significant difference in other color values (a*, b*, C* and h°). Soluble solids concentration (SSC) and total flavonoid content were significantly lower in fruit grown under red net than in control, and there was no significant difference in titratable acidity (TA), SSC/TA ratio, starch degradation and Streif maturity index. Red net proved to be effective against fruit red blush development (undesirable trait for 'Granny Smith' apple) and sunburn damage occurrence.

Inferring community assembly processes from functional seed trait variation along temperature gradient

Assembly of plant communities has long been scrutinized through the lens of trait-based ecology. Studies generally analyze functional traits related to the vegetative growth, survival and resource acquisition and thus ignore how ecological processes may affect plants at other stages of their lifecycle, particularly when seeds disperse, persist in soil and germinate. Here, we analyzed an extensive data set of 16 traits for 167 species measured in-situ in 36 grasslands located along an elevational gradient and compared the impact of abiotic filtering, biotic interactions and dispersal on traits reflecting different trait categories: plant vegetative growth, germination, dispersal, and seed morphology. For each community, we quantified community weighted mean (CWM) and functional diversity (FD) for all traits and established their relationships to mean annual temperature. The seed traits were weakly correlated to vegetative traits and thus constituted independent axes of plant phenotypical variation that were affected differently by the ecological processes considered. Abiotic filtering impacted mostly the vegetative traits and to a lesser extent on seed germination and morphological traits. Increasing low-temperature stress towards colder sites selected for short-stature, slow-growing and frost-tolerant species that produce small quantity of smaller seeds with higher degree of dormancy, high temperature requirements for germination and comparatively low germination speed. Biotic interactions, specifically competition in the lowlands and facilitation in uplands, also filtered certain functional traits in the study communities. The benign climate in lowlands promoted plant with competitive strategies including fast growth and resource acquisition (vegetative growth traits) and early and fast germination (germination traits), whereas the effects of facilitation on the vegetative and germination traits were cancelled out by the strong abiotic filtering. The changes in the main dispersal vector from zoochory to anemochory along the gradient strongly affected the dispersal and the seed morphological trait structure of the communities. Specifically, stronger vertical turbulence and moderate warm-upwinds combined with low grazing intensity selected for light and non-round shaped seeds with lower terminal velocity and endozoochorous potential. Synthesis: We clearly demonstrate that, in addition to vegetation traits, seed traits can substantially contribute to functional structuring of plant communities along environmental gradients. Thus, the hard seed traits related to germination and dispersal are critical to detect multiple, complex community assembly rules. Consequently, such traits should be included in core lists of plant traits and, when applicable, be incorporated into analysis of community assembly.

Rapid divergence in vegetative morphology of a wind-pollinated plant between populations at contrasting densities

Plant sexual dimorphism is thought to evolve in response to sex-specific selection associated with competition for access to mates or resources, both of which will often be density-dependent. In wind-pollinated plants in particular, vegetative traits can have an important influence on both resource acquisition and the pollen dispersal and receipt, with potential conflict between these two components of fitness. We evaluated the role of plant density in shaping plant traits by measuring evolutionary responses in experimental populations of the sexually dimorphic wind-pollinated plant Mercurialis annua. After three generations of evolution, we observed divergence between high- and low-density populations in several vegetative traits, whereas there was no divergence for reproductive traits. A reversal in the direction of sexually dimorphic traits expressed in young plants evolved in both low- and high-density populations compared to the original population (stored as seeds). Compared to the source population, males at high density evolved to be taller when young, whereas at low density young females tended to become smaller. These results demonstrate that a simple change in plant density can induce rapid, age-dependent and sex-specific evolution in the ontogeny of vegetative organs, and illustrates the power of experimental evolution for investigating plant trait evolution.

Assessing Physiological and Genetic Evidence for Evolution of Shared Weedy Rice Traits at the Vegetative Growth Stage

Weedy rice (Oryza spp.) has successfully adapted to invasion of cultivated rice (O. sativa L.) fields by being a strong competitor from the early vegetative growth stages to crop harvest. While seed shattering and seed dormancy have been shown to contribute to competitiveness at the reproductive stage, much less is known about the traits that could contribute to weedy rice adaptation at the vegetative stage. We examined several growth and physiological traits in five different weedy rice lineages with different ancestral origins, and found that no single vegetative phenotype characterizes all weedy rice. Divergence in growth and physiological traits between weedy rice groups and their putative cultivated ancestors has been limited, suggesting that altered vegetative traits have not been a common path to weed adaptation. There is a lack of convergence in patterns of gene expression in two independent weedy rice lineages, suggesting that there are few shared genetic mechanisms in the evolution of vegetative traits. We conclude that it must not be assumed that all weedy rice groups necessarily have altered vegetative growth or physiological mechanisms compared to their ancestors, that facilitate their invasion of crop fields.

Vegetative traits can predict flowering quality in Phalaenopsis orchids despite large genotypic variation in response to light and temperature

Phalaenopsis is an economically important horticultural ornamental, but its growth is slow and costly. The vegetative cultivation phase is long and required to ensure sufficient plant size. This is needed to develop high quality flowering plants. We studied the effects of temperature (27 or 31 °C) and light intensity (60 or 140 μmol m-2 s-1) on plant growth and development during the vegetative cultivation phase in two experiments, with respectively 19 and 14 genotypes. Furthermore, the after-effects of treatments applied during vegetative growth on flowering traits were determined. Increasing light intensity in the vegetative phase accelerated both vegetative plant growth and development. Increasing temperature accelerated vegetative leaf appearance rate, but strongly reduced plant and root biomass accumulation when temperatures were too high. Flowering was greatly affected by treatments applied during vegetative growth, and increased light and temperature increased number of flower spikes, and number of flowers and buds. Genotypic variation was large in Phalaenopsis, especially in traits related to flowering, thus care is needed when generalising results based on a limited number of cultivars. Plant biomass and number of leaves during vegetative growth were positively correlated with flowering quality. These traits can be used as an early predictor for flowering capacity and quality of the final product. Additionally, this knowledge can be used to improve selection of new cultivars.

DOTFL1 affects the floral transition in orchid Dendrobium Chao Praya Smile

A major obstacle for orchid (Orchidaceae)breeding and production is a long juvenile phase before orchid reproductive development. The molecular basis for prolonged vegetative growth in orchids remains largely unclear despite many efforts to clarify the relevant mechanisms. In this study, we report functional characterization of Dendrobium Orchid TERMINAL FLOWER1 (DOTFL1), an ortholog of TFL1 in Arabidopsis (Arabidopsis thaliana), from the orchid Dendrobium Chao Praya Smile. DOTFL1 is highly expressed in pseudobulbs and the shoot apical meristem (SAM) before and during the floral transition, but is downregulated in inflorescence apices and open flowers. Ectopic expression of DOTFL1 rescues the early-flowering and terminal-flower phenotypes of tfl1-20 in Arabidopsis. Overexpression of DOTFL1 in Dendrobium orchids delays flowering and produces defective inflorescence meristems and flowers with vegetative traits, whereas knockdown of DOTFL1 accelerates flowering and perturbs the maintenance of the inflorescence meristem. Notably, DOTFL1 suppresses orchid flowering and associated pseudobulb formation during the floral transition. We further reveal that two orchid MADS-box transcription factors, Dendrobium Orchid SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (DOSOC1) and AGAMOUS-LIKE 24 (DOAGL24), could interact with each other and bind to the CArG-box motif at DOTFL1, implying a regulatory hierarchy similar to their counterparts in Arabidopsis. Taken together, our findings suggest that DOTFL1 promotes vegetative growth, modulates successive developmental events required for reproductive success in Dendrobium orchids, and may have evolved with a previously unknown role in controlling pseudobulb formation in the Orchidaceae family.

Assessment of 60Co gamma radiation on early phenological stages of two generations of OFADA rice

Traditional Ofada rice varieties from South-West, Nigeria is preferred for its unique taste, aroma and massive potential for export but has low yield. Based on this background, two Ofada rice varieties, FUNAABOR 1 and FUNAABOR 2 were irradiated to create genetic variability as it affects vegetative traits. Seeds from the varieties were exposed to nine levels of 60Co gamma irradiation (0, 50, 100, 150, 200, 250, 300, 350 and 400 Gy). The seeds were nursed for 30 days before M1 seedlings were transplanted into a well tilled soil in a two factorial RCBD with three replicates. Selections from M1 plants were used to establish M2 plants generation. The results revealed diverse effects of 60Co gamma irradiation treatments on different plant vegetative traits. The establishment rates of M1 Ofada rice population were unaffected (p > 0.01) by increasing gamma irradiation from 0 to 300 Gy but decreased at 350 Gy. Above 300 Gy, tiller numbers, plant height, lodging incidence, leaf number, leaf length and leaf angle decreased significantly when compared with control (p < 0.01) in both generations (M1 and M2). Moderately tillered (10 tillers), tall plant (116.9 cm) obtained from 350 dosage rate recorded highest grain weight of 7.8 g per panicle. High phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) promoted by the irradiation dosages in M1 selection indicate the extent of environmental influence. High broad sense heritability observed from leaf number, leaf angle, leaf length, leaf blade colour, basal leaf sheath colour and grain weight per panicle shows possibility of rapid genetic improvement of these characters through selection.

Evaluation of Variance Components and Genetic Parameters in F1 Progenies of Coffea canephora Pierre x C. congensis Froehner

The diploid species Coffea congensis is of interest in improving the organoleptic quality of C. canephora. F1 crosses of C. canephora x C. congensis named Congusta in 3 x 5 factorial design have been carried out. The work aimed to assess the genetic parameters in the hybrids in order to integrate them into the selection schemes under way in Côte d'Ivoire. The experimental design was a randomized complete block design. Each cross was represented by a minimum of 29 plants and a maximum of 55 plants. The spacing used was 3 x 1.5 m. Male genotypes C. congensis brought little improvement in offspring regardless of their insignificant additive gene effect in the hybrids. Low heritabilities were found for vegetative vigor traits DICO, GAT and NPLA ranging from 0.13 to 0.23 in the narrow sense and from 0.18 to 0.32 in the broad sense. For production, the narrow sense heritabilities were stable during the first three years of harvest with values ​​between 0.23 and 0.25 whereas the broad sense heritability was irregular. The estimation GCA and SCA showed that all the traits except RCAR had ratio between both effects above 1. The study of correlations between traits showed insignificant correlations between production and vegetative traits, with coefficients below 0.30. However, The selection of 83 high-producing trees from 14 out of 15 studied families make it possible to create good vegetative trees linked to high yield.

The role of genus and life span in predicting seed and vegetative trait variation and correlation in Lathyrus, Phaseolus, and Vicia (Fabaceae)

ABSTRACTPREMISE OF THE STUDYAnnual and perennial life history transitions are abundant among angiosperms, and understanding the phenotypic variation underlying life span shifts is a key endeavor of plant evolutionary biology. Comparative analyses of trait variation and correlation networks among annual and perennial plants is increasingly important as new perennial crops are being developed in a predominately annual-based agricultural setting. However, it remains unclear how seed to vegetative growth trait relationships may correlate with life span.METHODSWe measured 29 annual and perennial congeneric species of three herbaceous legume genera (Lathyrus, Phaseolus, and Vicia) for seed size and shape, germination proportion, and early vegetative height and leaf growth over three months in order to assess relative roles of genus and life span in predicting phenotypic variation and correlation.KEY RESULTSGenus was the greatest predictor of seed size and shape variation, while life span consistently predicted static vegetative growth traits. Correlation networks revealed that annual species had significant associations between seed traits and vegetative traits, while perennials had no significant seed-vegetative associations. Each genus also differed in the extent of integration between seed and vegetative traits, as well as within-vegetative trait correlation patterns.CONCLUSIONSGenus and life span were important for predicting aspects of early life stage phenotypic variation and trait relationships. Differences in phenotypic correlation may indicate selection on seed size traits will impact vegetative growth differently depending on life span, which has important implications for nascent perennial breeding programs.