scispace - formally typeset
Search or ask a question

Showing papers on "Plant morphology published in 2017"


Journal ArticleDOI
TL;DR: The results suggest that SlPRE2 affects plant morphology and is a negative regulator of fruit pigment accumulation in tomato.
Abstract: The basic helix-loop-helix (bHLH) proteins are a large family of transcription factors that control various developmental processes in eukaryotes, but the biological roles of most bHLH proteins are not very clear, especially in tomato. In this study, a PRE-like atypical bHLH gene was isolated and designated as SlPRE2 in tomato. SlPRE2 was highly expressed in immature-green fruits, moderately in young leaves, flowers, and mature-green fruits. To further research the function of SlPRE2, a 35 S:PRE2 binary vector was constructed and transformed into wild type tomato. The transgenic plants showed increased leaf angle and stem internode length, rolling leaves with decreased chlorophyll content. The water loss rate of detached leaves was increased in young transgenic lines but depressed in mature leaves. Besides, overexpression of SlPRE2 promoted morphogenesis in seedling development, producing light-green unripening fruits and yellowing ripen fruits with reduced chlorophyll and carotenoid accumulation in pericarps, respectively. Quantitative RT-PCR analysis showed that expression of the chlorophyll related genes, such as GOLDEN 2-LIKE and RbcS, were decreased in unripening 35 S:PRE2 fruit, and carotenoid biosynthesis-related genes PHYTOENE SYNTHASE1A and ζ-CAROTENE DESATURASE in ripening fruit were also down-regulated. These results suggest that SlPRE2 affects plant morphology and is a negative regulator of fruit pigment accumulation.

57 citations


Journal ArticleDOI
TL;DR: It is confirmed that PGPMs may confer benefits in photosynthetic traits of soybean plants even in hydroponics (i.e., NFT), with positive effects on growth and seed production, prefiguring potential application of beneficial microorganisms in plant cultivation in hydoponics.
Abstract: The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximised by exploiting the action of plant growth-promoting organisms (PGPMs). However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [Glycine max (L.) Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. ‘Pr91m10’in closed nutrient film technique (NFT). Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control) plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs 247 n/mm2), thicker palisade parenchyma (95.0 vs 85.8 μm), and larger intercellular spaces in the mesophyll (57.5% vs 52.2%), compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis was higher in inoculated compared to control plants (8.69 vs 6.13 μmol CO2 m-2 s-1 at the beginning of flowering). These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants(0.807 vs 0.784 in control); conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area) and seed yield (+36.9%) compared to control. Our results confirm that PGPMs may confer benefits in photosynthetic traits of soybean plants even in hydroponics (i.e. NFT), with positive effects on growth and seed production, prefiguring potential application of beneficial microorganisms in plant cultivation in hydroponics.

41 citations


Journal ArticleDOI
TL;DR: The remodelling of the root architecture and the production of some secondary metabolites, such as IAA and phenols could be two responses of plants subjected to metal stress and can open the way to future phytoremediation strategies of contaminated sites.

37 citations


Journal ArticleDOI
TL;DR: The use of “new light” in greenhouse ornamentals is not only a technological change modifying plant morphology and development, but also affects the microbial ecology on plant surfaces, implying consequences on plant protection issues and biological control strategies.

25 citations


Journal ArticleDOI
TL;DR: Fagopyrum tataricum can be effectively induced into tetraploid plants by colchicines and can produce valuable germplasm resources for breeding and is a practicable breeding way in F. tatonicum.
Abstract: Tartary buckwheat are very popular as an important functional food material and its cultivation is very widespread in our whole world, but there obviously lack works in the researches of genetic breeding for agricultural and medicinal utilization. The aim of this study is to obtain good germplasm resources for agricultural and medicinal use of tartary buckwheat (Fagopyrum tataricum) by inducing the tetraploid plants. Four cultivars of F. tataricum, that is, Qianwei 2#, Jinku 2#, Chuanqiao 1#, and Liuqiao 1# were selected to experiment. The tips of seedlings with two true leaves were treated by 0.25% (w/v) colchicine solution for 48, 72, and 96 h, respectively. The chromosome number of treated plants was determined by metaphase chromosome counting of root tip cells and PMCs (pollen mother cells) meiosis observation. Tetraploid induction successfully occurred in all three treatments with an efficiency ranging from 12.13 to 54.55%. The chromosome number of the diploid plants was 2n = 2x = 16, and that of the induced tetraploid plants was 2n = 4x = 32. The typical morphological and physiological qualities were compared between the control diploid and corresponding induced tetraploid plants. Results showed that the induced tetraploid plants had obviously larger leaves, flowers, and seeds. Moreover, the content of seed protein and flavonoid were also increased in the tetraploid plants. The pollen diameter and capsule size of diploid plants were significantly smaller than those of tetraploid plants. Fagopyrum tataricum can be effectively induced into tetraploids by colchicines. The tetraploid induction can produce valuable germplasm resources for breeding and is a practicable breeding way in F. tataricum.

22 citations



Journal ArticleDOI
TL;DR: The results indicate that this environmental factor may not limit the displacement of populations towards sites with higher UV-B levels, and suggests thatUV-B is not the only factor involved in plants adaptation to high altitude environments.

15 citations


Journal ArticleDOI
TL;DR: The anatomic structure of the leaves, stem, and petioles of both species was conserved, even when exposed to different environments, but presented only subtle differences between species.
Abstract: Mikania glomerata and Mikania laevigata are medicinal plants popularly used in Brazil for colds and asthma. Although several studies report differences in their composition, they are frequently used indistinctly, which may be due to misidentification of the species or the plant part used. Herein, the chemical, anatomical, and morphological profiles of both species were evaluated, seeking to differentiate them. Due to the pattern of secondary metabolites found in M. glomerata and M. laevigata, the chemical profile of the leaves was the characteristic that best differentiated the two species. Coumarin was present in all the leaf samples of M. laevigata but absent or in low concentration in leaf samples of M. glomerata. The stems presented coumarin in both species, albeit in different concentrations. The quantification of chlorogenic and dicaffeoylquinic acids was crucial for the separation of the two species, as higher concentrations are found in M. glomerata. The anatomic structure of the leaves, stem, and petioles of both species was conserved, even when exposed to different environments, but presented only subtle differences between species. The morphology of the leaves presented different characteristics for each species but altered when exposed to shade. Therefore, the chemical analysis together with the morphological characteristics of plants grown in full sunlight may be used for the correct identification of these species.

14 citations


Journal ArticleDOI
TL;DR: Wang et al. as discussed by the authors proposed two major approaches for this issue: (i) the use of degradable mulch fi lm Cotton Root Morphology and Dry Matter Accumulation at Different Film Removal Times
Abstract: Agronomy Journa l • Volume 109, I s sue 6 • 2017 The Xinjiang Uygur Autonomous Region of China, an important cotton-growing region, is a typical irrigated arid area. Film covering and drip irrigation techniques have been employed since the early 1990s. Consequently, a unique technique of drip irrigation under plastic mulch fi lm (Hu and Li, 2003) was developed in Xinjiang through long-term practice. Th e features of water and fertilizer supply, that is, “low intensity with high frequency” and the eff ect of mulch fi lm in increasing soil temperature and conserving soil moisture have largely improved the per unit area yield of cotton (Jian et al., 2007; Rao et al., 2016). Th e cotton area in Xinjiang in 2014 (242 × 104 ha) was six times that of the 1990s (Statistical Bureau of Xinjiang Uygur Autonomous Region, 1990–2014). Currently, more than 50% of Chinese cotton production is supplied by Xinjiang, and more than 85% of the cotton fi elds in this region are covered with plastic mulch (Bai et al., 2015). However, the continuous use of mulch fi lm for years has led to increasingly serious pollution of mulch fi lm residue and has signifi cantly infl uenced cotton yield and soil production. Research fi ndings suggest that mulch fi lm residue in the cotton fi elds of Xinjiang has reached 18 kg ha–1 per year (Liang and Wang, 2012; Yan et al., 2008), and the average amount of fi lm residue in the soil aft er 20 yr is as high as 300.65 ± 49.32 kg ha–1 (Yan et al., 2008). If mulch fi lm is used for 68 yr consecutively (38 yr from now) without timely regulating measures, the mulch fi lm residue will reach 1 Mg ha–1 (Dong et al., 2013). Th e presence of a large amount of mulch fi lm residue in soil hinders the movement and distribution of water and N, obstructs the growth of crop roots (Li, 2016; Yang et al., 2016) and causes deterioration of soil physical-chemical properties, water maldistribution and soil nutrient decline. When the density of mulch fi lm residue reaches 2 Mg ha–1, alkali-hydrolyzale N and rapidly available P will decrease by 55.0 and 60.3%, respectively (Dong et al., 2013). Pollution control of mulch fi lm residue has become an urgent issue for agricultural production in Xinjiang and even the whole arid region. Currently, there are two major approaches for this issue: (i) the use of degradable mulch fi lm Cotton Root Morphology and Dry Matter Accumulation at Different Film Removal Times

10 citations


Journal ArticleDOI
17 Mar 2017-Genome
TL;DR: This research retrieved 23 GmPIN genes from the latest updated G. max genome database and focused on the artificial selection of the soybean PIN genes, providing useful and comprehensive basic information for understanding Gm PIN genes.
Abstract: Soybean (Glycine max) is one of the most important crop plants. Wild and cultivated soybean varieties have significant differences worth further investigation, such as plant morphology, seed size, ...

8 citations


Journal Article
TL;DR: The present study was undertaken to develop an effective protocol for optimum callus induction and organogenesis in Tinospora formanii, a rare endemic plant reported from Western Ghats of Kerala.

Book ChapterDOI
01 Jan 2017
TL;DR: The cultivated chickpea, Cicer arietinum, is a short annual herb with several growth habits ranging from prostrate to erect, and its hairs secrete a characteristic acid mixture which defends the plant against sucking pests.
Abstract: Chickpea is one of the important food legumes cultivated in several countries. It originated in the Middle East (area between south-eastern Turkey and adjoining Syria) and spread to European countries in the west to Myanmar in the east. It has several vernacular names in respective countries where it is cultivated or consumed. Taxonomically, chickpea belongs to the monogeneric tribe Cicereae of the family Fabaceae. There are nine annuals and 34 perennial species in the genus Cicer. The cultivated chickpea, Cicer arietinum, is a short annual herb with several growth habits ranging from prostrate to erect. Except the petals of the flower, all the plant parts are covered with glandular and non-glandular hairs. These hairs secrete a characteristic acid mixture which defends the plant against sucking pests. The stem bears primary, secondary and tertiary branches. The latter two branch types have leaves and flowers on them. Though single leaf also exists, compound leaf with 5–7 pairs of leaflets is a regular feature. The typical papilionaceous flower, with one big standard, two wings and two keel petals (boat shaped), has 9 + 1 diadelphous stamens and a stigma with 1–4 ovules. Anthers dehisce a day before the flower opens leading to self-pollination. In four weeks after pollination, pod matures with one to three seeds per pod. There is no dormancy in chickpea seed. Based on the colour of chickpea seed, it is desi type (dark-coloured seed) or kabuli type (beige-coloured seed). Upon sowing, germination takes a week time depending on the soil and moisture conditions.


Journal ArticleDOI
TL;DR: The effects of changes in leaf morphology and leaf architecture on plant light capture may explain the common occurrence ofheteroblastic species in the understorey of Neotropical forests, which does not negate a simultaneous positive effect of heteroblasty on plant water relations.

Dissertation
01 Mar 2017
TL;DR: It is discovered that the induction of phyllody is genetically linked with enhanced insect egg-laying preference on the infected plants that exhibit the leaflike flower phenotype, and SAP54 enhances insect colonisation of plants by suppression of insect-induced plant responses independent of developmental changes.
Abstract: Phytoplasmas are insect-transmitted plant pathogenic bacteria that dramatically alter plant development. Phytoplasma virulence protein (effector) SAP54 mediates degradation of host MADS-box transcription factors (MTFs) via 26S proteasome shuttle protein RAD23 to abolish normal flower development and produce leaf-like flowers (phyllody). Phyllodies are common symptoms in phytoplasma-infected plants worldwide. Why do phytoplasmas degrade MTFs and induce phyllody? Are changes in host plant morphology adaptive and benefit phytoplasma spread? Because phytoplasmas rely on their insect (leafhopper) vectors for transmission from plant to plant, I hypothesized that the vegetative tissues of the leaf-like flowers render plants more attractive to the insect vectors that will aid phytoplasma dispersal in nature. I discovered that the induction of phyllody is genetically linked with enhanced insect egg-laying preference on the infected plants that exhibit the leaflike flower phenotype. However, SAP54 enhances insect colonisation of plants independently from floral transition and the changes in plant morphology. Interestingly, male leafhoppers are required for the preference of females to lay eggs on SAP54 plants. Moreover, SAP54 suppresses insect induced plant responses in sex-specific manner by selectively downregulating male-induced defence and secondary metabolism pathways. Furthermore, I identified four MTFs that are expressed in plant leaves and play important roles in egg-laying preferences by leafhoppers and demonstrate sex-specific regulation by SAP54. Taken together, phytoplasma effector SAP54 enhances insect vector colonisation of plants by suppression of insect-induced plant responses independent of developmental changes. This is likely to occur by targeting MTFs – a conserved regulators of both plant development as well as plant defence against herbivorous insects. In addition to developmental changes, degradation of MTFs by SAP54 may result in modulation of male-induced plant responses to attract female insects for egg-laying and aid phytoplasma spread in nature.





DOI
01 Jan 2017
TL;DR: It appears that reduction in chestnut yield, recorded over recent decades, is associated with a decrease in the trees with longistaminate catkins, which are low yielding, but are fundamental for efficient pollination and the successive fertilization.
Abstract: Sweet chestnut (Castanea sativa Mill.) is a multi-purpose species cultivated for timber and nuts. However, recent years have seen a reduction in chestnut production. There are several reasons for this including abandonment of traditional cultivation practices, plant diseases, and problems during pollen differentiation. It appears that reduction in chestnut yield, recorded over recent decades, is associated with a decrease in the trees with longistaminate catkins, which are low yielding, but are fundamental for efficient pollination and the successive fertilization. Present study has been undertaken to provide new insights into the stamen and pollen morphology of four Andalusian chestnut cultivars (‘Helechal’, ‘Temprana’, ‘Vázquez’,‘Ancha de Alàjar’). It was observed that catkins in these cultivars are brachistaminate, and poor fertilization capability. The cultivar ‘Vázquez’ showed the longest stamens, and also the highest percentage of normal pollen and therefore, show highest fertilization capacity. On the other hand, shortest stamens and the lowest percentage of normal pollen grains, were recorded in cultivar ‘Ancha de Alàjar’ which cannot be considered a good pollinator.

Journal ArticleDOI
TL;DR: Key findings of this micro-morphological study were presence of numerous diacytic stomata on both adaxial and abaxial leaf surfaces, abundant glandular sessile trichomes on abaxian leaf surfaces and reticulate pollen ornamentation with echinate sulcus outlined with smooth morus that may serve as pharmacognostic markers aiding in accurate identification and quality control of this herb.
Abstract: Does the adaptive plant morphology actually hint at its potential bioactive profile? To understand and decipher this, a micro-morphological investigation was conducted on an arid zone plant . Andrographis serpyllifolia (Rohl.ex.vahl.) Wight is a slightly bitter, acrid endemic herb with fair history of ethno-botanical use among different tribes of peninsular India. A. serpyllifolia was a highly evolved geophyte well-suited for high survivability in extremely harsh terrain. This plant was found to grow and perpetuate successfully under high-stress conditions of water deficit, high soil and atmospheric temperatures, poor nutrition and constant threat from herbivores. Under such circumstances, this plant possessed the potential to develop morphological adaptations that produce and accumulate a wide range of phytochemicals that could preserve, protect and defend its plant body. The twin objectives of this study were to investigate the micro-morphological features and their functional advantage that enabled the plant to flourish in adverse conditions and interpret by deductive reasoning, the potential phytochemical array of this plant given the observed features. Scanning electron microscope was used to explore surface morphologies of various vegetative and floral parts. Key findings of this micro-morphological study were presence of numerous diacytic stomata on both adaxial and abaxial leaf surfaces, abundant glandular sessile trichomes on abaxial leaf surfaces, reticulate pollen ornamentation with echinate sulcus outlined with smooth morus and deeply reticulate, highly pitted spermoderm or seed testa reminiscent of human brain. These three features may serve as pharmacognostic markers aiding in accurate identification and quality control of this herb.


Journal ArticleDOI
TL;DR: The present investigation to asses the extent of genetic variability, heritability, correlation and path co-efficient analysis of 60 genotypes of brinjal for yield and shoot and fruit borer tolerance concluded that the maximum phenotypic and genotypic variation was noted.
Abstract: The present investigation was carried out in the Department of Horticulture, Faculty of Agriculture, Annamalai University, during the period 2014 - 2015 to asses the extent of genetic variability, heritability, correlation and path co-efficient analysis of 60 genotypes of brinjal for yield and shoot and fruit borer tolerance. The experiment was laid out in Randomized Block Design with three replications. From the analysis of data, it can be concluded that the maximum phenotypic and genotypic variation was noted for fruit yield per plant (67.94 and 67.27%) followed by fruit weight (50.70 and 50.41%), fruit girth (30.72 and 29.88%), number of fruits per plant (29.99 and 29.79%) followed by shoot and fruit borer incidence (21.59 and 21.37%). High heritability along with high estimates of GCV, genetic advance and genetic gain was observed for fruit yield per plant, fruit weight, number of secondary branches per plant and shoot and fruit borer incidence. Among the sixteen morphological characters studied, number of long styled flowers per plant (8.803), number of short styled flowers per plant (5.403), number of fruits per plant (3.099), fruit weight (0.757), days to first harvesting (0.133) and shoot and fruit borer incidence (0.082) showed positive direct effect in path co-efficient analysis. Positive correlation was recorded for fruit weight (0.885), fruit girth (0.644) and number of fruits per plant (0.622).



Journal ArticleDOI
TL;DR: The studied cultivars demonstrated favorable characteristics for ornamental usage based on visual assessments, and ‘Grecco a Palla’ showed the highest germination speed index and seed germination percentage.
Abstract: Basil ( Ocimum spp.) is an essential oil producing plant and it is used as a condiment for diferent foods, besides serving as raw material for medicinal purposes. This crop has also been showing great importance as an ornamental plant in recent years. However, basil lacks studies concerning its different usages with special regards to its ornamental potential. Therefore, this study aimed at evaluating the vegetative development and the ornamental potential of the basil cultivars ‘Grecco a Palla’ ( O. minimum ), ‘Alfavaca Basilicao Vermelho’ ( O. basilicum ), and ‘Thai Basil’ ( O. basilicum ), under protected cultivation. The following characteristics were evaluated: germination percentage, germination speed index, plant canopy diameter (cm), leaf and inflorescence length (cm), plant height (cm), and fresh and dry leaf mass (g). The ornamental potential was estimated based on visual evaluations of plant canopy volume; leaf shape, texture, size, and color; stem and flower color; and number of days to flowering. Cultivar ‘Thai Basil’ presented the highest leaf dry mass and ‘Grecco a Palla’ showed the highest germination speed index and seed germination percentage. All cultivars bloomed within 60 days after planting and exhibited color and brightness variability, which are desirable traits for a landscape composition. ‘Grecco a Palla’ stood out for its short and compact inflorescences, dwarf size and globular shape when grown as a potted plant. The studied cultivars demonstrated favorable characteristics for ornamental usage based on visual assessments.

Journal ArticleDOI
TL;DR: Twenty diverse genotypes of cucumber collected from Tamil Nadu and Kerala regions were evaluated for morphological characters like days to first female flowering, node number of first female flower, vine length, number of secondary branches, fruit length, fruit girth and 1000 seed weight.
Abstract: Twenty diverse genotypes of cucumber collected from Tamil Nadu and Kerala regions were evaluated for morphological characters like days to first female flowering, node number of first female flower, vine length, number of secondary branches, days to fruit harvest, fruit length, fruit girth, fruit diameter, average fruit weight, number of fruits per plant, 1000 seed weight and yield per plant to estimate the variability, heritability, genetic advance. In variability studies, yield per vine was obtained highest mean value CS 6 genotype. Maximum phenotypic and genotypic co-efficient of variation (PCV and GCV) was for yield per plant followed by average fruit weight, fruit diameter and number of fruits per plant. High heritability was observed for all the characters except node number of first female flower. Genetic gain was maximum for yield per plant followed by average fruit weight, fruit diameter, number of fruits per plant, number of secondary branches, fruit length, fruit girth and 1000 seed weight.

Journal ArticleDOI
TL;DR: A wide variation in the susceptibility of the cultivars to stem borer herbivory is reported, and the implementation of cultural practices seems to be a promising alternative for the management of borer species, to which Amaranthus is particularly vulnerable.

01 Jan 2017
TL;DR: The aim of this study was to identify and assess the mechanisms andoys that contribute to the change in the behaviour of tree species in sistemas agroflorestais through the course of an active period of time.
Abstract: Submetido em 14/07/2016 e aprovado em 14/06/2017 . 1Universidade Federal de Santa Maria, Campus Frederico Westphalen, Departamento de Ciência Agronômicas e Ambientais, Frederico Westphalen, Rio Grande do sul, Brasil. denise@ufsm.br; otomarcaron@yahoo.com.br; ninepilau@yahoo.com.br; nardinoagronomia@yahoo.com.br; elvisfelipeelli@yahoo.com *Autor para correspondência: elvisfelipeelli@yahoo.com Morfoanatomia foliar de azevém no sub-bosque de espécies arbóreas em sistemas agroflorestais A verificação das modificações que ocorrem na planta, em função da aclimatação ao sombreamento, auxilia na seleção de espécies forrageiras adequadas para o uso em sistemas agroflorestais. O objetivo deste estudo foi avaliar a morfoanatomia foliar de azevém ( Lolium multiflorum Lam.), no sub-bosque de espécies arbóreas em sistemas agroflorestais. O experimento foi conduzido no município de Frederico Westphalen, RS, entre junho e setembro de 2012, em delineamento experimental de blocos ao acaso. O azevém anual foi semeado em três ambientes: radiação solar plena, sub-bosque de angico-vermelho ( Parapiptadenia rigida Benth.) e canafístula ( Peltophorum dubium Spr. Taubert), com três repetições. As espécies florestais foram distribuídas em cinco renques, separados por 6,0 m cada. Foram avaliadas as seguintes variáveis: radiação fotossinteticamente ativa incidente (RF Ai), transmissividade da RF Ai, área foliar específica, espessura do mesofilo foliar , espessura da parede periclinal externa mais cutícula, tamanho do estômato e densidade estomática. A presença das espécies florestais provoca alterações nas condições luminosas do ambiente de produção do azevém e ocasiona ajustes nas folhas dessa espécie, os quais resultam no aumento da área foliar específica, na diminuição do mesofilo e na espessura da parede periclinal externa mais cutícula, bem como no aumento da quantidade e tamanho dos estômatos. Esses ajustes resultam da capacidade de aclimatação do azevém, que nas condições de baixa luminosidade, altera sua morfologia em busca de radiação solar e aumenta a área fotossintética. Palavras-chave: Lolium multiflorum; aclimatação; sombreamento. Denise Schmidt , Braulio Otomar Caron , Janine Pilau, Maicon Nardino, Elvis Felipe Elli * 10.1590/0034-737X201764040005 Leaf morphoanatomy of ryegrass in the tree species understory in agroforestry systems The verification of changes that occur in the plant, due to the acclimatization to the shading, assists in the selection of forage species suitable for use in agroforestry systems. The aim of this study was to evaluate the leaf morphoanatomy of ryegrass ( Lolium multiflorum Lam.) in the tree species understory in agroforestry systems. The experiment was conducted in Frederico Westphalen, RS, Brazil, between June and September 2012, in an experimental design of randomized blocks. The annual ryegrass was sown in three environments: full sunlight, understory of angico-vermelho (Parapiptadenia rigida Benth.), and canafístula ( Peltophorum dubium Spr. Taubert), with three replications. Forest species were distributed in five lines, separated by 6.0 m. The following variables were evaluated: incident photosynthetically active radiation (RF Ai), transmissivity of RFAi, specific leaf area, leaf mesophyll thickness, thickness of outer periclinal wall + cuticle, stomatal size, and stomatal density . The presence of forest species causes changes in the lighting conditions of the production environment of ryegrass and causes adjustments in the leaves of this species, which result in increased specific leaf area, decreased mesophyll and thickness of the outer periclinal wall + cuticle, as well as increased amount and size of the stomata. These adjustments result from the acclimation capacity of ryegrass, which, in low-light conditions, alter their morphology to capture more solar radiation and increase the photosynthetic area.