Tiller Growth Research Articles

Recovery from short-term complete submergence in temperate pasture grasses

The ability to recover from the impact of short-term submergence was assessed on four widely used grasses in pastures: Dactylis glomerata L., Bromus catharticus Vahl., Schedonorus arundinaceus Schreb. (syn. Festuca arundinacea) and Phalaris aquatica L. Six-week-old plants were subjected to a 5-day complete submergence in clear water, followed by a 15-day recovery period. Dry mass after submergence, shoot and root growth, number of tillers per plant, leaf stomatal conductance and leaf greenness during recovery were assessed. Dactylis glomerata and B. catharticus were sensitive to submergence, showing very low relative growth rate (RGR) of shoots and roots during recovery (37–67% lower than controls) along with early leaf senescence and persistent partial stomatal closure. Schedonorus arundinaceus exhibited an intermediate tolerance, sustaining high RGR of shoots (similar to controls) and fully adjusting its leaf functionality during recovery despite being affected during submergence (40% decrease in dry mass and 37% in tiller number). Phalaris aquatica performed outstandingly, with dry mass unaffected by submergence, and unaltered stomatal conductance, leaf greenness, tillering and shoot growth during recovery. Therefore, in areas where flooding can often cause plant submergence, P. aquatica is recommended whereas the other species are not, because they may be outcompeted by flood-tolerant species.

PEMBERIAN PUPUK DAUN CAIR Silicon Fertilizer (SF) PADA SEMAI AKASIA DAUN KECIL (Acacia auriculiformis A.Cunn) DENGAN MEDIA SEMAI BOKASHI

The research aimed was knowing the effect of concentration of liquid silicone fertilizer fertilizer (SF) on growth of Acacia auriculiformis A.Cunn seedling. This research was conducted at the location of seedling SMK Darul Amin West Waru, District Waru Pamekasan, altitude of about 100 m asl. Research using Completely Randomized Design (RAL) where the concentration of fertilizer is considered as treatment so that there are 4 concentrations of fertilizer. Media seedlings used, namely Media Bokashi with the ground with a ratio of 70%: 30%. Repetition is done 5 times. The main parameters observed were a live presentse calculated at the end of the study, plant height, stem diameter, and number of leaves. The results showed the number of live tillers was 100%. treatment did not give a real effect on the growth of tillers, where F count was 1.44. For stem diameter F arithmetic of 0.111, also increase the number of leaf F count equal to 1.31. Of the three parameters F count is smaller than F tebel 5% = 2.67 and F table 1% = 4.43. So in the treatment of concentration of liquid leaf fertilizer Silicon Fertilizer (SF) (A1, A2, A3 and A4) showed no significant effect on the increase of height, increase in diameter and number of leaves.

Does cross-acclimation between drought and freezing stress persist over ecologically relevant time spans? A test using the grass Poa pratensis.

Despite evidence that prior exposure to drought can increase subsequent plant freezing tolerance, few studies have explored such interactions over ecologically relevant time spans. We examined the combined effects of drought and subsequent freezing on tiller growth and leaf sugar concentrations in the grass, Poa pratensis. We exposed tillers to no drought (-0.04 MPa), moderate drought (-0.19 MPa) or severe drought (-0.42 MPa) for 3weeks in summer. Tillers were then frozen in autumn or spring at -5°C (frost damage) or at 0°C (control) for 3days and harvested after a re-growth period. For shoot growth, there was a significant interaction between drought and autumn freezing, whereby the relative effect of freezing on growth was least for the plants previously exposed to severe drought; however, there was no significant interaction between drought and spring freezing. For root growth, there were no significant interactions between drought and freezing in either season. Leaf sugar concentrations increased significantly with drought intensity, but these effects dissipated within a month, prior to the onset of the autumn freezing treatment. Overall, our results suggest that interactions between prior drought and subsequent freezing in P.pratensis may be most relevant in the context of autumn freezing, and despite the important role of soluble sugars in increasing both drought and freezing tolerance in this species, the retention of these compounds after drought stress does not appear to explain the occurrence of drought-frost interactions at ecologically relevant time scales.

Divergent effects of defoliation intensity and frequency on tiller growth and production dynamics ofPascopyrum smithiiandHesperostipa comata

Rotational stocking theoretically enables regrazing of regrowth, but regrowth may be limited in xerophytic vegetation. We tested the hypothesis that regrowth would be slow and fixed in Hesperostipa comata (a caespitose, drought-tolerant grass), while growth would be flexible in Pascopyrum smithii (a rhizomatous, less drought-tolerant grass) under increasing defoliation and moisture, by assessing tiller growth rates, population dynamics and plant yield on marked plants in a Dry Mixed Grass prairie. Plots were clipped in late summer to simulate a deferred control, or intermittently during the growing season (May–August) at high intensity–low frequency (HILF), low intensity–high frequency (LIHF) or high intensity–high frequency and crossed with two water treatments (ambient and addition) in both a xeric upland and a mesic lowland. Growing season defoliation increased tiller growth rates of P. smithii in the upland, whereas HILF and LIHF reduced growth in the lowland. All defoliation regimes increased tiller growth for H. comata. Tiller populations of H. comata increased with frequent defoliation, while tiller populations of P. smithii decreased regardless of defoliation regime. Frequent defoliation, regardless of intensity, reduced yield relative to the deferred control for both grasses. While water addition consistently increased growth rates and reduced differences in tiller number among defoliation treatments, the regrowth of both grasses remained similar under varied defoliation with ambient moisture. High moisture conditions also promoted regrowth more in P. smithii compared to H. comata. In summary, neither grass species displayed an inherently fixed or flexible tiller or plant yield response in response to defoliation or moisture.

Effect of Crop Establishment Methods and Varieties on Tillering Habit, Growth Rate and Yield of Finger-Millet

Effect of Crop Establishment Methods and Varieties on Tillering Habit, Growth Rate and Yield of Finger-Millet

Grazing Intensity and Phenotypic Plasticity in the Clonal Grass Leymus chinensis

Phenotypic plasticity enables plants to cope with changes in their environment. Plasticity in a population of Leymus chinensis, a common grass species in arid and semiarid temperate grasslands of northern China, was determined in a natural grassland grazed by large domestic herbivores. We measured shoot and bud characteristics monthly along a grazing intensity gradient indicated by distance from the village gate during two growing seasons. In addition, some plants along the gradient were removed to a common transplant garden and their growth was compared. Leaf characteristics (leaf angle, leaf length, and leaf number), growth form (tiller height and tiller clusters), bud proliferation, and plant fitness differed significantly in situ along the gradient. The expression of plasticity was grazing intensity dependent: the greatest increase in tiller density, tiller cluster, and bud number occurred at a moderate grazing intensity (2.5 km from the village gate). In the transplant garden, no evidence was found for distinct populations of L. chinensis within the grassland. Leaf characteristics, tiller growth form, and bud demography of tillers not grazed showed phenotypic plasticity in response to grazing of neighbor shoots because clonal reproduction is the main breeding system for this species in grazed natural grassland and defoliation of neighbor shoots is likely to affect the physiology and morphology of tillers that are not grazed. The observed overcompensation in vegetative reproduction may aid future survival and growth and could be achieved in a prudent grazing system designed to take into account the needs of this dominant grass in semiarid temperate steppes.

Drought inhibition of tillering in Festuca arundinacea associated with axillary bud development and strigolactone signaling

Drought stress inhibits tiller formation and growth, but the underlying mechanism is not well understood. Tiller development and lateral branch growth in monocot and dicot species respectively involve two stages: axillary bud initiation and subsequent outgrowth. The objective of this study was to investigate whether drought-inhibition of tiller growth is mainly due to the suppression of axillary bud initiation or subsequent outgrowth in perennial grass species and to determine whether drought-inhibition of tiller development and growth in grass species are associated with strigolactone (SL) accumulation and signaling. Seedlings with one fully-expanded leaf without axillary buds and those with three-fully expanded leaves and two axillary buds were grown in 20% polyethylene glycol (PEG) solution to induce drought stress. Plant height, number of leaves, axillary buds, tillers and length of axillary buds were monitored during 21 d of stress. Both axillary bud initiation and outgrowth were inhibited by drought stress, with outgrowth being more sensitive to drought stress. qRT-PCR analysis showed that expression level of genes involved in axillary bud activity was down-regulated at 14 d of drought stress while genes involved in axillary bud dormancy was up-regulated. Strigolactone (SL) content was elevated under drought stress in crowns. qRT-PCR analysis showed that expression level of genes involved in SL biosynthesis and signaling transduction were up-regulated during drought stress. Axillary bud outgrowth was sensitive to drought stress and could be associated with SL signaling, contributing to drought-inhibition of tillering in perennial grass species.

Seasonal Trends of Tiller Emergence and Senescence in Several Temperate Herbage Grasses Grown under Sward Conditions

Seasonal Trends of Tiller Emergence and Senescence in Several Temperate Herbage Grasses Grown under Sward Conditions

Pengaruh Jenis Bonggol dan Konsentrasi Ba terhadap Pertumbuhan Vegetatif P pada Tanaman Pisang Kepok Manado

This study aimed to (1) determined the effect of BA concentration on the growth of banana seedlings origin hump cleavage. (2) determined the effect of different origin banana weevil seedling growth and tuber production of tillers. (3) determined the effect of BA concentration on the growth of seedlings and saplings of origin hump hump production. This research has been carried out in January 2013 to April 2013 in the Integrated Field Laboratory, University of Lampung, Bandar Lampung. The design of the experiment using a randomized block design with 3 replications were once created as a test group. Grouping is done based on the size of the hump and time of observation. Arranged in a factorial design of treatment (4 x 2) consisting of two factors; The first factor is the concentration of benzyladenine (BA) consists of 4 levels of concentration are: 0, 50, 100, and 150 ppm. The second factor is the hump that comes from plants that have been producing, and tubers of plants are still puppies. The results showed: (1). Use of BA with a concentration of 50, 100 and 150 ppm had no significant effect on all the variables of observation. (2). Type tuber production yield better growth than puppies hump seen from the variable leaf length, root length, leaf width, number of roots, and the girth so it better be made for seedlings compared with seedling tubers. (3) Pemberian BA with various concentrations of either the production or hump hump tillers showed no difference in the growth of shoots. Keywords: nursery, benzyladenine, hump production, hump tillers

15N tracer-based analysis of genotypic differences in the uptake and partitioning of N applied at different growth stages in transplanted rice

Nitrogen (N) fertilizer split-application is the most widely adopted N management in rice production. To investigate the genotypic differences in the uptake of fertilizer-N applied at different growth stages and in the partitioning of accumulated N in transplanted rice, a two-year field experiment using a split–split plot design with two N rates (105 and 210kgha−1) and three 15N-labelled fertilizer application treatments was conducted in three rice varieties with different fertilizer-N recovery efficiencies (FNREs). The FNRE of total fertilizer was measured, and the FNREs of basal, tillering and panicle fertilizations were analyzed by applying 15N-labelled urea as basal, tillering or panicle fertilizer. Although the panicle-FNRE (32%-68%) was greater than the FNREs of both basal and tillering fertilizers (10%–36% and 13%–42%, respectively), the FNRE of total fertilizer was significantly and positively correlated with both basal and tillering-FNREs (p<0.01). The high-FNRE varieties absorbed more basal fertilizer-N compared with the low-FNRE variety and had significantly greater basal-FNRE and percentages of basal fertilizer-N in the stems at heading and in the panicles at maturity. Early and quick tillering emergence was observed in the high-FNRE varieties, and there was a significant positive relationship between basal-FNRE and tillering rate. The above results indicate that the difference in basal fertilizer-N absorption plays an important role in the genotypic difference in FNRE, and high-FNRE varieties might be selected from the varieties characterized by fast tillering in the early growth stages.

Biofertilizing potential of feather hydrolysate produced by indigenous keratinolytic Amycolatopsis sp. MBRL 40 for rice cultivation under field conditions

Abstract Extracellular keratinase-producing strain Amycolatopsis sp. MBRL 40 exhibited antifungal activity against four important rice fungal pathogens and plant growth promoting traits such as indole 3-acetic acid (IAA) production and phosphate (P) solubilization. The strain could produce IAA in the degraded feather medium (3 µg/ml) and increased production was observed when the medium was supplemented with 0.2% tryptophan (7 µg/ml). The strain could solubilize significant amounts of tricalcium P (117 µg/ml). Rice seeds treated with MBRL 40 showed higher germination percentages and vigor indices, and enhanced seedling growth over control under gnotobiotic conditions. Under field conditions, rice plants grown in presence of dried hydrolysate pellet (P), hydrolysate filtrate (S) and feather hydrolysate with bioinoculant (B+F) exhibited significantly enhanced growth and higher number of tillers per plant over plants grown in the absence of urea (C-). However, P treated plants did not have enhanced growth in all the parameters in comparison to plants treated with S and B+F. Rice grown in presence of B+F was found to exhibit better growth over plants grown in presence of P and S. Rice grown in presence of urea (C+) and B+F showed similar levels of growth promotion.

Revisiting Domestication to Revitalize Crop Improvement: The Florigen Revolution

Most flowering plants have evolved to coordinate proper floral transition in shoot apical meristems at an appropriate time during development, referred to as “flowering time.” In domesticated crops, shoot life time has been manipulated to enhance productivity via synchronizing flowering time to the local environment, thereby creating a balance between vegetative and reproductive plant architecture during the year. Rice, a typical single transitional crop, has acquired balance between prolonged tiller growth and a relatively short reproductive phase on individual shoot, resulting in increasing yield. Crops with sympodial growth, such as tomato, which undergo multiple floral transitions on the main shoot, have been artificially selected for the determination of shoot growth by investigating the dosage sensitivity of florigen activation controlling flowering time on individual shoots. Here, we summarize recent genetic-molecular studies on tomato, which have been subject to genetic manipulation of flowering time in an effort to optimize seed productivity. We also review advanced genetic approaches as potential new tools for the enhancement of crop yield by manipulating flowering time via the dosage effect of florigen.

Exogenously applied gibberellic acid improves the growth and yield performance of inferior rice tillers grown under different nitrogen levels

Inferior tillers typically provide a minimal contribution to the grain yields of rice; however, with the proper regulation of light and nutrients, their yields may be significantly enhanced. The exogenous introduction of gibberellic acid (GA3) may assist with extending the culm lengths of inferior tillers, the sequestration of additional sunlight, and the accumulation of further nutrients. In an attempt to verify our assumption while enhancing the grain yield of inferior tillers, GA3 was applied to inferior tillers under different nitrogen (N) levels. Morphological alterations, photosynthetic parameters, endogenous GA content, N accumulation, and soluble sugars within the leaves of inferior tillers were assessed, as was the activity of sucrose synthase (SuSase) in the cleavage direction. Our results revealed that the belated emergence and low concentration of endogenous GA1+3 translated to the stunted growth of inferior tillers, which ultimately had a reduced capacity to harvest sunlight. Furthermore, insufficient sunlight due to asymmetric competition might be the source of the reduction of inferior tiller source and sink activities. Foliar GA3 spray enhanced the intercepted photosynthetically active radiation (IPAR) and SuSase activity in inferior tillers considerably; however, dry matter and N accumulation provided adequate resources to grains only when the tillers obtained sufficient N. The alterations in soluble sugars indicated that inferior tillers did not respond well to the application of GA3 under an insufficient N supply. In contrast, when sufficient N was made available, GA3-treated inferior tillers received high-intensity light, and additional energy was allocated to the photochemical reactions of photosystem II (PSII). The high quantum efficiency of PSII contributed to the transportation of C- and N-assimilates from the source organ to the sink under adequate N conditions, and eventually increased the grain yields of the inferior tillers.

재식밀도 및 파종기 이동에 따른 기장(Panicum miliaceum L.)의 분얼발생 양상 및 생육 특성

재식밀도 및 파종기 이동에 따른 기장(Panicum miliaceum L.)의 분얼발생 양상 및 생육 특성

Heterogeneity in Rice Tillers Yield Associated with Tillers Formation and Nitrogen Fertilizer

Rice (Oryza sativa L.) farmers generally overcome low seeding rates with additional nitrogen (N) fertilization to develop more productive tillers. However, not every tiller provides high productivity; instead, a sufficient N source leads to the production of tillers with low yield potential. The objectives of this study were (i) to quantify the heterogeneity within tillers regarding yield formation at different N levels and (ii) to examine the differences in tiller growth period, grain yield, and carbon (C) and N concentrations at different N levels. In 2013 to 2014, field experiments consisted of a randomized complete block design with three N fertilizer rates. Gini coefficient was adopted to analyze the heterogeneities of various tillers regarding grain yield. Results showed that tiller heterogeneity was enhanced with increasing N levels. Under the same N rate condition, the grain yield of productive tillers decreased with the later‐emerging tillers. The early‐emerging tillers possessed the characteristics of long growth period, strong intercepted photosynthetic active radiation, and high C/N ratio in straw. The N‐induced enhancement in rice population mainly occurred due to the increase in grain yield of early‐emerging tillers. However, this upward trend would emerge peak value after sufficient N supply. Therefore, analyzing the limiting factors for low production of late‐emerging tillers may provide a novel perspective on further improving the rice population yield.Core Ideas Heterogeneity in rice tillers yield is increased with increasing N rates. Short growth period is not the key limiting factor to late‐emerging tillers. Early‐emerging tillers pre‐empt the uppermost light source and shade the late‐emerging tillers. Early‐emerging tillers possess higher C/N ratio in straw than late‐emerging tillers. Late‐emerging tillers have higher yield potential under sufficient N supply.

Triacontanol Reduces Transplanting Shock in Machine-Transplanted Rice by Improving the Growth and Antioxidant Systems.

Machine transplantation results in serious transplant shock in seedlings and results in a longer recover stage, which negatively impacts the growth of low-position tillers and the yield of machine-transplanted rice. A barrel experiment was conducted to examine the effect of the foliar application of triacontanol (TRIA) on machine-transplanted rice during the recovery stage. TRIA (0, 1, 5, and 10 μM) was sprayed over leaves 2 days before transplanting. The chlorophyll content, sucrose content, oxidative damage, antioxidant enzyme levels, glutathione (GSH), and ascorbate (ASA) redox states, tiller dynamics and yield components of the plants were investigated. The results show that foliar-applied TRIA significantly alleviates the growth inhibition and oxidative damage caused by transplant shock. Furthermore, the application of TRIA increased the chlorophyll and sucrose contents of the plants. Importantly, TRIA not only significantly improved the activity of catalase (CAT) and guaiacol peroxidase (POD), demonstrating that POD can play an important role in scavenging H2O2 during the recovery stage, but it also enhanced the redox states of ASA and GSH by regulating the activities of enzymes involved in the ASA–GSH cycle, such as ascorbate peroxidase (APX) and glutathione reductase (GR). A dose of 10 μM TRIA was the most efficient in reducing the negative effects of transplant shock, increasing the panicles, grain filling, and grain yield per hill by 17.80, 5.86, and 16.49%, respectively. These results suggest that TRIA acts to reduce transplant shock in association with the regulation of the redox states of ASA and GSH and antioxidant enzymes and serves as an effective antioxidant to maintain photosynthetic capacity and promote the occurrence of low tillers.

English

Field experiments were conducted at Cropping Systems Research Centre, Karamana, Thiruvananthapuram, Kerala during summer/third crop/puncha season in 2007 and 2008 to find out the effect of nutrient sources under different management systems. The experiment was laid out in split plot design with four replicates. The treatments consisted of four management systems, viz., System of Rice Intensification SRI (M1), Integrated Crop Establishment Method (ICM) (M2), Package of Practices (PoP) (M3) of Kerala Agricultural University and Conventional Management Practices (M4) in main plot. Nutrient sources, such as organic sources (S1), integrated nutrient sources (S2) and inorganic sources (S3) were the sub plot treatments. Conventional management practices (M4) recorded higher values of growth (height of plants, number of leaves hill-1, leaf area index (LAI) and number of tillers per unit area) and yield attributes (No. of productive tillers m-2, grain and straw yield). Sources of nutrients did not influence growth characters in Njavara. Among the nutrient sources, higher number of grains panicle-1, filled grains panicle-1 and crop yield (grain and straw) were recorded under integrated nutrient source than organic and inorganic sources. The maximum net return (30,562 Rs ha-1) and B:C ratio of 2.40 were also noted under the conventional management practices with integrated nutrient source. Key words: Rice establishment techniques, economics, productivity, Njavara rice.

Nitrogen use of Panicum and Brachiaria cultivars vary with nitrogen supply: I. Differences in plant growth

Tropical grass pastures are broadly split between those that use high N fertilizer rates and those that use little or none. Maximizing the efficiency of N application in pastures requires understanding which features and adaptations species utilize to take advantage. This study was designed to determine the variation in growth of Brachiaria cultivars (Basilisk, Marandu, Piata and Xaraes) and Panicum cultivars (Aruana, Massai, Mombaca and Tanzania) under two N supply rates (low and high) in order to understanding forage-grass species adaptive mechanisms for high and low N supply. Changes in growth were determined based on the following characteristics: number of leaves and tillers, leaf area (LA), shoot dry matter (SDM) production, root surface area (RSA), root length (RL) and root dry matter(RDM) production. The experimental design consisted of 8 forage-grass cultivars x 2 N rates (30 and 300 mg dm -3 ) in a randomized block design with four replications. At low N supply, Marandu, Xaraes, Piata, Basilisk and Mombaca cultivars maintained a constant number of tillers but showed a decrease in the number of leaves and LA compared to high N. Tanzania cultivar maintained a constant number of tillers and LA but showed a decrease in the number of leaves under low N. In contrast, cultivars Aruana and Massai showed an increased number of tillers and a reduced LA. At low N rate, Brachiaria cultivars prioritized roots growth but with high N supply increased leaf and tiller growth. Brachiaria cultivars demonstrated high plasticity of reserve allocation, suggesting that these cultivars may better withstand N stress, ensuring their persistence. Panicum cultivars exhibited vigorous roots growth which may improve the capture of soil N and reduce losses from leaching and volatilization, and also can contribute to reduce environment contamination.

ソルガム品種「風立」の主茎，分げつの生育および収量に及ぼす栽植密度の影響

ソルガム品種「風立」の主茎，分げつの生育および収量に及ぼす栽植密度の影響

The PIN1 family gene PvPIN1 is involved in auxin-dependent root emergence and tillering in switchgrass.

Switchgrass (Panicum virgatum L.; family Poaceae) is a warm-season C4 perennial grass. Tillering plays an important role in determining the morphology of aboveground parts and the final biomass yield of switchgrass. Auxin distribution in plants can affect a variety of important growth and developmental processes, including the regulation of shoot and root branching, plant resistance and biological yield. Auxin transport and gradients in plants are mediated by influx and efflux carriers. PvPIN1, a switchgrass PIN1-like gene that is involved in regulating polar transport, is a putative auxin efflux carrier. Neighbor-joining analysis using sequences deposited in NCBI databases showed that the PvPIN1gene belongs to the PIN1 family and is evolutionarily closer to the Oryza sativa japonica group. Tiller emergence and development was significantly promoted in plants subjected toPvPIN1 RNA interference (RNAi), which yielded a phenotype similar to that of wild-type plants treated with the auxin transport inhibitor TIBA (2,3,5-triiodobenzoic acid). A transgenic approach that inducedPvPIN1 gene overexpression or suppression altered tiller number and the shoot/root ratio. These data suggest that PvPIN1plays an important role in auxin-dependent adventitious root emergence and tillering.