Length Of Secondary Roots Research Articles

Pengaruh Tinggi Tapak Timbun Terhadap Distribusi Akar Kelapa Sawit (Elaeis guineensis Jacq.) Umur 10 Tahun Pada Lahan Mineral

One of the reasons for the low productivity of oil palm is the lack of proper technical culture implementation. The implementation of technical culture practices that can be carried out includes stem mounding by creating mound platforms for the oil palm. This study aims to determine the effect of mound bed height on the growth and development of roots in 10-year-old oil palm plants. The research was conducted experimentally using a Non-Factorial Randomized Complete Block Design with 5 levels of mound bed height: 20 cm, 25 cm, 30 cm, 35 cm, and 40 cm. Each treatment was replicated five times, resulting in 25 experimental units. Each experimental unit consisted of three sample plants, making a total of 75 sample plants. The observed parameters included fresh root weight, dry root weight, the number of primary roots, the length of primary roots, the number of secondary roots, the length of secondary roots, and the number of tertiary roots. The results of the study indicated that the mound bed treatment on 10-year-old oil palm plants in mineral soil, particularly at a height of 40 cm, tended to increase the fresh root weight by 2.45 g, the dry root weight by 0.65 g, the number of tertiary roots by 5.26 strands, the number of primary roots by 2.80 strands, the length of primary roots by 10.0 cm, the number of secondary roots by 2.26 strands, and the length of secondary roots by 2.61 cm.

A preliminary evaluation of phenotypic traits of tepary bean (Phaseolus acutifolius A. Gray)

Background: Tepary bean (Phaseolus acutifolius A. Gray) is an underutilised grain legume crop and important source of food, nutrition and income. To date, there are no significant breeding efforts aimed at cultivar development and the crop remains under-utilised and under-researched.Aim: Therefore, the aim of this study was to evaluate eight phenotypic traits and their relationships among 42 genotypes of tepary bean in a controlled drought screening greenhouse environment.Setting: Agricultural Research Council – Vegetable, Industrial and Medicinal Plants, South Africa in drought screening glasshouse.Method: A 6 × 7 rectangular lattice design replicated three times was used in the study.Results: There were highly significant (p 0.01) differences in all the phenotypic traits that were measured. The highest number (30) of secondary roots was recorded for genotype ‘Ac-39’, which exceeded the trial, mean value by 62.87%. In comparison with the check, only Ac-33’, ‘Ac-39’, ‘Ac-40’ and ‘Ac-7’, ‘Ac-8’, ‘Ac-40’, ‘Ac-41’ genotypes achieved a significantly (p 0.05) higher secondary root length (SRL) and shoot dry weight (SDW), respectively. A highly significant (p 0.01) positive association was observed between the shoot fresh weight and the SDW suggesting that there was a strong linear relationship between the two parameters. Similarly, at least 68.0% of the changes in root dry weight were attributed to the changes in the SRL.Conclusion: These results suggested that the observed phenotypic variability in this germplasm which could be exploited for the enhancement of tepary bean.Contribution: There will be merit in validating these results on a field basis together with grain yield evaluation and genotyping over multiple locations and seasons to determine elite germplasm for production and utilisation by growers.

Air Layering in Guava (Psidium guajava L.) as Influenced By IBA and Polywrappers

The experiment was conducted employing randomized block design with three replications, and the study consists of 12 treatment combinations in total using different concentration of Indolebutyric acid (IBA) in liquid, powder and paste form as well as using of white polywrappers (WP) and black polywrappers (BP). The best treatment was T11 with IBA Powder form@ 10000 ppm + BP which showed the highest root and growth parameters. With respect to number of primary roots, length of primary roots, diameter of primary roots, number of secondary roots, length of secondary roots, diameter of secondary roots, and dry weight of roots, T11was found superior. At 90 days after planting,70% success in rooting, 71.02% survival percentage, number of shoots per layer 7.78 and 15.56 number of leaf per plant was significantly (p>0.05) found higher as compared to other treatment combinations. Further, T8 (IBALiquid @ 10000 ppm + BP secured second position whereas minimum values were recorded in T3with IBA Paste @ 5000 ppm + White polywrapper.

Response of Indole 3 butyric acid during air layering on root and shoot induction behavior in Guava (Psidium guajava L) CV Sardar (L-49)

Air layering is practiced as it has assured to produce true to type plants and early and better rooting is observed when treated with Indole-3-butyric acid (IBA). A field experiment was conducted to study the Rooting and shooting behaviour in Guava (Psidium guajava L.) air layering under different concentrations of IBA during 2019 in guava orchard located at Maheru, Lovely Professional University, Phagwara, Punjab. A total of ten treatments with three replications comprising T1 –Control, T2- IBA@ 5 g, T3- IBA@ 6 g, T4- IBA@ 7 g, T5- IBA@ 8 g, T6- IBA@ 9 g, T7- IBA@ 10 g, T8- IBA@ 11 g, T9- IBA@ 12 g, T10- IBA@ 5000 ppm (Liquid) were applied. Thirteen observations of the root and shoot characters were recorded and analyzed in factorial design of RBD. The results indicated that IBA@ 8 g (T5) performed better than control and produced the best results in root parameters and shoot parameters such as the number of days to root (31.7), primary roots (59.30), primary root length (8.74 cm), primary root diameter (0.89 mm), secondary roots (45.57), secondary root length (5.73 cm), fresh root weight (0.93 g) and dry root weight, (0.81g) number of side shoots (6.87), length of side shoots (4.10 cm), length of longest side shoots (6.01 cm) and number of leaves per air layer (33.93). The existing guava production is not able to meet our present demand of guava fruits to the increasing population of the country. It is commonly propagated by seed. However, the seedlings produced are not true to type and they also take much longer to bear fruits than asexually propagated materials as the juvenile phase is eliminated in asexually propagated plants. Therefore, in the present study, guava air layering plants treated with the IBA@ 8 g are true to type and do not take much time to bear fruits, thus contributing to quality guava production.

Root System Architecture and Symbiotic Parameters of Summer Mung Bean (Vigna Radiata) under Different Conservation Agriculture Practices

Root system architecture plays a vital role in plant growth, development, and adaptation by absorbing water and nutrients and providing mechanical support for growing plants. Unfortunately, little information is available in the literature on the root dynamics of summer mung bean under conservation agriculture conditions. In this study, field experiments were conducted during the summer seasons of two consecutive years (2020 and 2021) to investigate the root system dynamics of summer mung bean under different conservation agriculture practices. The highest stem and system width, depth to width length, number of nodal roots, taproot diameter, secondary root length (both right and left) of summer mung bean were recorded in the Soybean (permanent bed; PB)-Wheat(PB)-Summer mung (PB)(+Residual; +R) based cropping systems, followed by Maize(PB)-Wheat(PB)-Summer mung (PB)(+R), while, the lowest values of above parameters were recorded in the Puddled Transplanted Rice–Conventional till (PTR-CT)Wheat-Summer mung (-R). Further, the pod length, number of seeds per pod, number of pods per plant, seed yield and symbiotic parameters (including number of nodules per plant, leghaemoglobin content) and root dry weight were recorded highest in Soybean (PB)-Wheat (PB)-Summer mung (PB)(+R). Interestingly, the yield of summer mung bean increased around 13.4–29.5% when residues were retained on the soil surface with treatments involving residual removal. The soil dehydrogenase enzyme activity increased significantly under Soybean (PB)-Wheat (PB)-Summer mung (PB)(+R) based cropping system as compared to PTR-CT Wheat-Summer mung (-R). In addition, the number of pods per plant exhibited a significantly positive correlation with yield during both crop seasons. Overall, this study suggests that the inclusion of summer mung in soybean-based cropping systems may substantially improve the root architecture and soil quality and increase crop yield under conservation agriculture.

Effect of different growing media, Azotobacter and GA3 on growth and survivability of transplanted air layers in Guava (Psidium guajava L.) C.V. Gwalior-27

The present investigation entitled “Effect of different growing media, Azotobacter and GA3 on growth and survivability of transplanted air layers in Guava (Psidium guajava L.) C.V. Gwalior- 27” was conducted at Experimental block, College of Agriculture, R.V.S.K.V.V., and Gwalior (M.P.) during the year 2020-2021. The experiment was laid out in Completely Randomized Design (CRD) with three replications. Among different treatments Soil +Vermicompost (2:1) + GA3 200 ppm + Azotobacter (0.5ml) resulted in maximum survival percentage of air layers at DAT 135 (87.33%) followed by the treatment with Soil + Leaf mould (2:1) + GA3 200 ppm + Azotobacter (0.5ml) (77.43%). This treatment also enhanced the growth as well as root parameters of air layers, No. of Sprouts at 15 DAT (8.67), No. of leaves (37.00),Stem length (28.33cm), and Stem thickness (16.20 mm), Number of primary roots (10.00), Number of secondary roots (21.67), and Length of primary roots (11.97 cm), Length of secondary roots (8.73cm), Diameter of primary roots (3.27 mm), Diameter of secondary roots (2.00 mm),Fresh weight of primary roots (1.84g), Fresh weight of secondary roots (0.79g) at 135 DAT. It may be concluded that Soil +Vermicompost (2:1) + GA3 200 ppm + Azotobacter (0.5ml) was found best for highest survivability percentage and enhanced root parameters followed by Soil + Leaf mould (2:1) + GA3 200 ppm + Azotobacter (0.5ml).

Gibberellins regulate lateral root development that is associated with auxin and cell wall metabolisms in cucumber

Cucumber is an economically important crop cultivated worldwide. Gibberellins (GAs) play important roles in the development of lateral roots (LRs), which are critical for plant stress tolerance and productivity. Therefore, it is of great importance for cucumber production to study the role of GAs in LR development. Here, the results showed that GAs regulated cucumber LR development in a concentration-dependent manner. Treatment with 1, 10, 50 and 100 μM GA3 significantly increased secondary root length, tertiary root number and length. Of these, 50 μM GA3 treatment had strong effects on increasing root dry weight and the root/shoot dry weight ratio. Pairwise comparisons identified 417 down-regulated genes enriched for GA metabolism-related processes and 447 up-regulated genes enriched for cell wall metabolism-related processes in GA3-treated roots. A total of 3523 non-redundant DEGs were identified in our RNA-Seq data through pairwise comparisons and linear factorial modeling. Of these, most of the genes involved in auxin and cell wall metabolisms were up-regulated in GA3-treated roots. Our findings not only shed light on LR regulation mediated by GA but also offer an important resource for functional studies of candidate genes putatively involved in the regulation of LR development in cucumber and other crops.

Effect of different growing media, Azotobacter and GA3 on growth and survivability of transplanted air layers in Guava (Psidium guajava L.) C.V. Gwalior-27

The present investigation entitled “Effect of different growing media, Azotobacter and GA3 on growth and survivability of transplanted air layers in Guava (Psidium guajava L.) C.V. Gwalior - 27” was conducted at Experimental block, College of Agriculture, R.V.S.K.V.V., and Gwalior (M.P.) during the year 2020-2021. The experiment was laid out in Completely Randomized Design (CRD) with three replications. Among different treatments Soil + Vermicompost (2:1) + GA3 200 ppm + Azotobacter (0.5 ml) resulted in maximum survival percentage of air layers at DAT 135 (87.33%) followed by the treatment with Soil + Leaf mould (2:1) + GA3 200 ppm + Azotobacter (0.5ml) (77.43%). This treatment also enhanced the growth as well as root parameters of air layers, No. of Sprouts at 15 DAT (8.67), No. of leaves (37.00), Stem length (28.33 cm), and Stem thickness (16.20 mm), Number of primary roots (10.00), Number of secondary roots (21.67), and Length of primary roots (11.97 cm), Length of secondary roots (8.73 cm), Diameter of primary roots (3.27mm), Diameter of secondary roots (2.00 mm), Fresh weight of primary roots (1.84 g), Fresh weight of secondary roots (0.79 g) at 135 DAT. It may be concluded that Soil +Vermicompost (2:1) + GA3 200 ppm + Azotobacter (0.5 ml) was found best for highest survivability percentage and enhanced root parameters followed by Soil + Leaf mould (2:1) + GA3 200 ppm + Azotobacter (0.5 ml).

Morphological Characteristics of Sugar Palm [Arenga Pinnata Merr.] Seedling Growth Based on Cotyledon Petiole Position

Sugar palm is a bioenergy plant with great potential in food security, biopolymers, biofuel, and herbal medicine. Sugar palm seed germination is indicated by the appearance of cotyledon petiole, where there are several different positions. Morphological characteristics of sugar palm seeds at various positions of cotyledon petiole are not currently available. This research aimed to study the morphology characters of sugar palm seedlings with different cotyledon petiole positions. The research applied Experiment in Completely Random Design with four treatments, each repeated three times. The four treatments are the cotyledon petiole position, namely P1: cotyledon petiole in right-center, P2: cotyledon petiole in left-center, P3: cotyledon petiole in left-bottom, and P4: cotyledon petiole in right-bottom. The results showed that morphologically, there was no significant difference in the sugar palm seedling growth with each cotyledon petiole position [256 DAS]. Range of seed height 47,63-57,50 cm, range number of leaf midribs 2-3,33, range of primary root length 13,73-21,76 cm and, range of secondary root length 28,60-44,26 cm.

Results of Practical Use of Fertilizers from Chicken Manure in Winter Wheat Cultivation

The article considers utilization of organic waste from poultry farming being an urgent problem of agriculture. Leaders of large poultry farms are interested in using low-cost recycling schemes aimed to process waste into safe products in a short time. This paper considers the possibility of using an organic fertilizer “Soil Improver (UP-1)” obtained by processing poultry waste by using a biologically active additive Mefosfon, which is a melamine salt of bis (oxymethyl) phosphinic acid. Field tests were carried out in 2019-2020 on the lands of OAO “Agrofirma “Ak Bars-Pestretsy” being the branch of the Poultry farm of the Pestrechinsky district of the Republic of Tatarstan. The object of the study was the recognized variety of soft winter wheat “Scepter” ES (elite variety). The rate of application of chicken compost and organic product UP-1 in the control and experimental plots was 56 tons per 1 ha. The experimental data show that wheat cultivated with the application of UP-1 compost was distinguished by higher rates of field germination (increased by 13 %); the length of secondary roots was 11.2 % greater compared to control. The grain produced in this variant had higher hardness (control – 62 %, UP-1 – 72 %) and the quality of crud gluten (74.0, 78.0 %, respectively), the yield of winter wheat grain – by 0.06–0.12 t/ha (1.2–2.5 %), which indicates the feasibility of using fertilizer from poultry manure in crops cultivation.

The effects of rooting media, IBA, and clones on rooting ability of Teak’s shoot cutting

Clonal forestry of teak in the community forest could increase the forest productivity where the shoot cutting was one of the vegetative propagation methods to propagate and maintain the superior clone of teak. However, the major problem on the shoot cutting of teak was the difference in rooting ability among rooting media, IBA (Indolebutyric Acid) and selected superior of teak clone. The research was conducted on split-split plot design with 10 individual as replication on each treatment. The main plot was two rooting media (cocopeat:rice husk 2:1/A; and soil:sand:compost 3:2:1/B). The subplot was IBA hormone concentration (0 ppm, 50 ppm, 100 ppm, 150 ppm) and the sub-sub plot was 11 clones of teak. The result showed that the rooting ability of teak was affected by all of treatments and interaction among them (P < 0.05), except for the interaction between IBA dosage and clone (P >0.05). The primary and secondary root length showed that clone and interaction between media and clone were significantly different (P < 0.05), while the media was only significantly different for secondary root length (P < 0.05). However, the number of primary and secondary root was not affected by the treatments (P>0.05). Moreover, the best result of rooting ability of teak for rooting media, IBA and was the cocopeat:rice husk (70,53%), IBA 150 ppm (53.18%) and clone WG2 (85%), respectively. It suggested that the seedling production of superior teak through the shoot cutting method depended on the rooting media, IBA concentration, and the specific of teak clone.

Effects of some properties of cedar forest soils on secondary roots of Cedrus atlantica Manetti

The effect of textural and physicochemical characteristics of five cedar forest soils on 4- and 8-month-old seedlings of Cedrus atlantica Manetti was studied in a controlled growth chamber. During their growth, cedar seedlings show a change in the root architecture by the levels of C&lt;sub&gt;org&lt;/sub&gt;, N, P, and by the soil granulometry. The Tioumlilin soil conditions stimulate mainly the cumulative length and the number of secondary roots. However, the cedar forest soil of Tazekka predominates over most soils in its effect on growth by the balance of chemical elements and the high percentage of coarse particles. The analysis of the densities of secondary and tertiary roots and the cumulative length of secondary roots show four different root architectural development strategies of C. atlantica seedlings which may justify the low level of mycorrhization on young seedlings in the natural cedar forest soil. The variations of the root architectural parameters of C. atlantica seedlings are discussed in relation to the characteristics of cedar forest soils.

Changes in Root Architecture After Amino Acid Application in a Soybean Crop

Improving the root system favors better plant growth, since it promotes water and nutrient absorption, resulting in higher plant yield. In this respect, the use of products for this purpose has become promising. Applying amino acids has benefitted the root system of Arabidopsis and in some vegetables; however, little is known about their influence on soybean plants. As such, the aim of this study was to assess the effect of applying amino acids to seeds and leaves on the root architecture of soybean plants. Effects of amino acids such as glutamate, cysteine, glycine and phenylalanine on the main root length (MRL), total root length (TRL), projected area (PA), root volume (RV), number of secondary roots (NSR), secondary root length (SRL) and number of tertiary roots (NTR) were evaluated. All the amino acids studied improved root architecture. Seed-applied cysteine increased TRL by 55%, in relation to control. When applied on leaves, it raised TRL by 27% and MRL by 69%, compared to control. Applying glycine to seeds increased MRL by 54%, PA by 69%, RV by 96% and NTR by 119%, all in relation to control. Thus, amino acids enhanced the architecture of soybean roots. However, glutamate, glycine and phenylalanine produced better responses when applied to seeds, and cysteine, when applied to leaves. All of these changes may help roots absorb more water and nutrients, thereby raising crop yield.

Propagation of Valuable North Sumatera Benzoin Trees (Styrax Sp) Using Macrocutting Technique

Kemenyan known as Sumatran benzoin is North Sumatera local species that produce high valuable rosin and prospective export comodities. However, sustainability of Sumatran benzoin production has many constraints such as instability of resin production, lack information of propagation technique and traditional management system. Until now, comprehensive information for Sumatran benzoin propagation system still not determined yet. The objectives of this research were (1) to get information about propagation technique of Sumatran benzoin and its suitable growing medium and 2) to get information on adventitious root formation in Sumatran benzoin cuttings. Cutting materials (Toba benzoin and Durame benzoin) were originated from 1 year old seedling propagated by seed. Media used were combination of sand : rice husk (1:0 v/v; 1/1 v/v). Results showed that interaction between media and benzoin species significantly affected primer and secondary root lenght. While planting medium significantly improved secondary root length and number. Benzoin species significantly affected primary and secondary root lenght, and secondary root number.

Screening of exotic and indigenous apple rootstocks for different horticultural traits

An experiment was carried out to find the suitable exotic as well as indigenous apple rootstocks for temperate zone of India. The rootstocks were screened on the basis of 11 important pomological traits. The data revealed that maximum numbers of primary and secondary roots were noted of 93.40, 92.76 in MM.106 and USA 106 and 92.0 noted in CITHrootstock- 01, respectively. Maximum length of primary roots (19.83cm) was recorded of EMLA 106 whereas shortest primary roots (6.47 cm) were recorded of ALNARP. The longest secondary roots (11.83cm) were found in M.27 and shortest secondary roots (2.10 cm) in ALNARP rootstock. Most of the indigenous apple rootstocks were having short to medium length of secondary roots. Leaf area was recorded highest (3.80cm2) in CITH-Apple rootstock-04 and smallest (1.96 cm2) of USA- 106. All the evaluated rootstocks have pink colored petiole except B-9, which has dark red color. Highest collar rot incidence was observed in M- 27 and M-26 and least in indigenous root stocks (CITH-Apple rootstocks). Highest wooly aphid infection was found in M-9, B-9, M-27, EMLA-106 and ALNARP whereas least infestation noted in M-26 and indigenous apple rootstock (CITH-ARS-01, CITH-ARS-02, CITH-ARS-03, CITH-ARS-04, CITH-ARS-, CITH-ARS-09 and CITH-ARS-10). Primary root length has positive correlation with secondary root numbers, secondary root length and leaf petiole length but negative correlation with leaf area.SAARC J. Agri., 14(2): 117-125 (2016)

PERCEPATAN KEMAMPUAN BERAKAR DAN PERKEMBANGAN AKAR STEK PUCUK Shorea platyclados MELALUI APLIKASI ZAT PENGATUR TUMBUH IBA

Shorea platyclados is one of fast-growing Dipterocarp species for enrichment planting in Logged-Over Area (LOA) of tropical rain forests. One of the constrain to supply the seedling for support enrichment planting is the irregular flowering of S. platyclados. Moreover, the vegetative propagation is an alternative method to provide the sustainable seedling for enrichment planting in the LOA. This experiment was carried out to assess the effects of IBA concentrations on rooting ability, the primary and secondary root lengths, and the accumulated number of primary and secondary roots on shoot cutting of S. platyclados. The research was conducted in Completly Randomized Design (CRD) with 5 replications. The treatment was five concentrations of IBA, i.e. 0 ppm, 25 ppm, 50 ppm, 75 ppm, and 100 ppm. The data were analyzed using one-way analysis of variance (one way ANOVA) to determine the effect of IBA concentration variation amongst the treatments. The Duncan Multiple Range Test (DMRT) was used for multiple comparisons among the means of treatment at tα=5%, Results showed IBA concentrations significantly affected the rotting ability, the primary and secondary root length of shoot cutting (P 0.05). For rooting ability, 100 ppm of IBA concentration was the highest of all treatments. Meanwhile, 75 ppm of IBA concentration was the best treatment for development of root, i.e. the number of primary roots, the length primary and secondary roots.

Effect of waterlogging at different growth stages on some morphological traits of wheat varieties.

Excess rainfalls may be the cause of waterlogging in soil, which affects the growth and development of wheat. Therefore, the objectives of this study were to examine the effects of waterlogging on shoot and root growth and physiological characteristics of wheat. Three experiments were conducted: experiment 1 (E1): evaluation of seedling growth on ten Iranian winter wheat varieties with waterlogging periods (1-4, 4-8, 8-12, and 12-16 days starting from seed germination). Seminal roots and plumule were investigated at seedling. The others are E2: pretreatment of waterlogging (15days) at tillering and stem elongation stages and its effects on shoot and root growth at anthesis stage and experiment 3 (E3): pretreatment of waterlogging (15days) at tillering and jointing stages and its effects on yield and yield components and also evaluation of stress tolerance indexes. The results of the seedling growth test (E1) showed that 1-4- and 4-8-day waterlogging severity reduced seminal root length (94.5 to 93.7%) and plumule length (86.2 to 50.0%) compared to control. Results of E2 indicated that waterlogging stress decreased shoot dry weight, root dry weight, total secondary root length, and chlorophyll a + b content of flag leaf by 28-31, 44-35, 20-31, and 28-35%, respectively. Also, result of E3 showed that the grain yields of wheat varieties at two conditions of stress were different in base tolerance indexes. In general, the responses of wheat varieties to waterlogging were different at the three experiments. The varieties that had the most of dry weight and length of the root were tolerant. Thus, it is possible to use these characteristics as an index for selecting the varieties with tolerance to waterlogging.

Effect of Preconditioning Treatments and Auxins on the Rooting of Semi-Hardwood Cuttings of Olive Planted During Winter Under Mist Condition

An experiment was conducted during winter to find the effect of girdling, etiolation and auxins i.e. IBA and NAA on rooting of semi- hardwood cuttings of olive cv. Leccino under mist. The experiment comprised of 13 treatments and was combinations of girdling, etiolation and auxins. The results indicated that the best rooting characteristics viz; highest percent rooted cuttings (53.33), number of primary roots (6.58) and secondary roots (8.53) and diameter (0.46 mm) were maximum with cuttings treated with IBA at 5000 ppm, where as the maximum primary root length (5.30 cm) and secondary root length (2.42) was recorded with the treatment girdling + IBA 4000 ppm + NAA 1000 ppm and IBA 4000 ppm, respectively. Regarding the shoot characteristics viz; plant height (14.59 cm) was recorded highest for the treatment IBA@ 4000 ppm which was at par with the treatment IBA @ 5000 ppm (14.26 cm). Highest plant diameter (2.40 mm), numbers of leaves (16.26) and leaf area (36.42 cm2) were highest for the treatment IBA @ 5000 ppm. Survival percentage of cuttings (71.57 %) was also highest in cuttings treated with IBA @ 5000 ppm. It is concluded that IBA at 5000 ppm was found to be the best treatment for propagation of olive through semi- hardwood cuttings during winter.

Influence of rhizobacterial volatiles on the root system architecture and the production and allocation of biomass in the model grass Brachypodium distachyon (L.) P. Beauv.

BackgroundPlant growth-promoting rhizobacteria are increasingly being seen as a way of complementing conventional inputs in agricultural systems. The effects on their host plants are diverse and include volatile-mediated growth enhancement. This study sought to assess the effects of bacterial volatiles on the biomass production and root system architecture of the model grass Brachypodium distachyon (L.) Beauv.ResultsAn in vitro experiment allowing plant-bacteria interaction throughout the gaseous phase without any physical contact was used to screen 19 bacterial strains for their growth-promotion ability over a 10-day co-cultivation period. Five groups of bacteria were defined and characterised based on their combined influence on biomass production and root system architecture. The observed effects ranged from unchanged to greatly increased biomass production coupled with increased root length and branching. Primary root length was increased only by the volatile compounds emitted by Enterobacter cloacae JM22 and Bacillus pumilus T4. Overall, the most significant results were obtained with Bacillus subtilis GB03, which induced an 81 % increase in total biomass, as well as enhancing total root length, total secondary root length and total adventitious root length by 88.5, 201.5 and 474.5 %, respectively.ConclusionsThis study is the first report on bacterial volatile-mediated growth promotion of a grass plant. Contrasting modulations of biomass production coupled with changes in root system architecture were observed. Most of the strains that increased total plant biomass also modulated adventitious root growth. Under our screening conditions, total biomass production was strongly correlated with the length and branching of the root system components, except for primary root length. An analysis of the emission kinetics of the bacterial volatile compounds is being undertaken and should lead to the identification of the compounds responsible for the observed growth-promotion effects. Within the context of the inherent characteristics of our in vitro system, this paper identifies the next critical experimental steps and discusses them from both a fundamental and an applied perspective.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0585-3) contains supplementary material, which is available to authorized users.

Ferulic acid impairs rhizogenesis and root growth, and alters associated biochemical changes in mung bean (Vigna radiata) hypocotyls

The present study investigated the effect of ferulic acid (FA; 0–1000 µM) on early growth, and rhizogenesis in mung bean (Vigna radiata) hypocotyls and associated biochemical changes. FA severely affected the radicle elongation and number of secondary roots after 72 h. The root and shoot length, number and length of secondary roots, and seedling dry weight of one-week-old seedlings of mung bean were decreased by 64%. The rooting potential (percent rooting, number and length of adventitious roots) of mung bean hypocotyls under in vitro conditions was significantly inhibited in response to 1–100 µM FA. At 1000 µM there was complete cessation of rooting. FA caused a reduction in the contents of water-soluble proteins and endogenous total phenolics, whereas the activities of proteases, peroxidases, and polyphenol peroxidases increased. The study concludes that FA inhibits root growth and development, and in vitro rooting process in mung bean by interfering with biochemical processes that are crucial for root formation.