Bud Germination Research Articles

Effect of time, techniques and environment of propagation on performance of guava (Psidium guajava)

An experiment was conducted at Horticultural Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology-Meerut, to study the effect of time and techniques of propagation on bud/graft success and quality parameters in guava (Psidium guajava L.). Maximum survival percent (82.30) was recorded with patch budding performed in March under shade condition. Wedge grafting recorded minimum number of days to bud sprout (13.86 days) under shade conditions whereas, patch budding had recorded maximum number of days to bud sprout (36.86 days) under open conditions. The sprouting percentage of budded or grafted plant was higher under shade condition than open condition. Based on results obtained in the present study, it may be concluded that, patch budding was found to be better over wedge grafting in respect of survival, sprouting, plant and growth traits.

Effects of different ways of flower bud differentiation on bud germination and fruit quality of grape

In this study, 3 year-old ‘Xiahei’ grape was used as the test material. It aimed to promote the differentiation of grape flower buds with different concentrations of paclobutrazol and chlormequat chloride, and the effects of different ways of promoting the differentiation of flower buds on the germination of grape buds and fruit quality were studied. The results showed that different ways of flower bud differentiation could promote the germination of ‘Xiahei’ grape buds. In consideration of the fruiting habit, phenological period and fruit quality of different treatments, second fruits which were sprayed with 1000 times 15% paclobutrazolin had the best effect. On May 1, 2019 (One fruit sitting period) spraying grape new tip with 1000 times 15% paclobutrazol and 0.3% potassium dihydrogen phosphate, 0.1% boric fertilizer and the same fungicides, spraying again after 7 days, reagent type and concentration were same as the first time, after 10 days of the second spraying 2.5% hydrogen cyanamide was used to break dormancy of winter bud. The way could effectively promote grape secondary fruit and improve the quality of the grapes.

Canopy Modification Influences Growth, Yield, Quality, and Powdery Mildew Incidence in Tas-A-Ganesh Grapevine

ABSTRACTA field trial was conducted to study effect of different canopy modifications on growth, yield, quality, and disease incidence in Tas-A-Ganesh grapevine grafted onto Dogridge rootstock. Ten-years-old vines trained to extended Y training system with three types of canopy modifications [Single Cordon Horizontal (SCH), Double Cordon Horizontal (DCH), and Four Cordon Horizontal (FCH)] were selected for study. The vines had horizontally placed cordon with vertically positioned shoot on the cordon. Results of different canopy modification demonstrated that, among the vegetative growth parameters studied, pruning weight and shoot length was significantly higher in DCH. Days to bud sprout and cane diameter had no significant influence of any of the canopy modifications studied. Significant differences were observed for leaf area index, photosynthesis rate, stomatal conductance, and transpiration rate. The vines trained to DCH had higher rate of photosynthesis. Yield per vine and number of bunches per vine was higher in FCH. Maximum total soluble solids (TSS) was recorded in SCH. Total acidity was increased with increase in cordons from SCH to FCH. Lower concentration of total acids was recorded in SCH (0.56%). We observed that as bunch load increased, TSS was reduced while total acidity was increased. The disease assessment data from different canopy modifications revealed that powdery mildew incidence was significantly increased from SCH to FCH with increase in canopy density. The results supported with concentration of lower phenols in powdery mildew-infected canopy (FCH). The results revealed that the canopy with DCH canopy modification performed better for growth and yield and reduced disease incidence.

Effects of a biodegradable liquid film on winter chill protection of winegrape cultivars

In China, according to the climatic zoning, more than 90% Vitis vinifera are distributed in areas where the vines must be buried under a layer of soil during winter (vine burial) to protect them from severe winter chill (Li et al., 2006; Wang et al., 2018). Vine burial in winter followed by vine excavation and straightening in spring are difficult and expensive tasks, posing risks to the plants and the environment. Therefore, the goal of this work was to identify a biodegradable liquid film (BLF) suitable for grapevine application to replace vine burial as an alternate strategy to protect against winter chill. We evaluated the influence of BLF spraying on vines after being trained in winter (BLF spraying treatment) and compared it with vine burial (VB). The study evaluated the grapevine death rate of BLF treatment following freezing events in January 2016, and compared germination date, yields, berry quality, and a cost analysis of the two treatments during the winter of 2015 to the spring of 2017 at Heyang Station of Viticulture, NWAFU, in China. The results showed that BLF application can protect some cultivars from winter chill in Heyang and delays bud germination date in cold years. BLF treatment has the opposite trend of reducing sugar and titratable acid content for Cabernet Sauvignon and Italian Riesling, causes higher polyphenols content of berries under most conditions, and requires lower winter vineyard operations costs than VB treatment.

Effects of Leaf Age and Exogenous Hormones on Callus Initiation, Rooting Formation, Bud Germination, and Plantlet Formation in Chinese Fir Leaf Cuttings

To guide the cultivation of superior Chinese fir plantlets, we designed an L16(4)4 orthogonal experiment to determine how leaf age and exogenous hormones influence key growth processes in leaf cuttings. Hormone concentration and treatment duration significantly affected leaf cuttings in all three age categories; 6-benzylaminopurine (6-BA), 1-naphthaleneacetic acid (NAA), and treatment time exerted the strongest effects on callus initiation rates. Additionally, NAA had the largest effect on the rooting rate across all cuttings, and all three hormones significantly influenced the bud germination rate. Based on our experimental results, expected optimal treatments for callus initiation were 10 mg∙L−1 indole-3-butyric acid (IBA) for 10 min, 30 mg∙L−1 NAA for 15 min, and 10 mg∙L−1 NAA plus 30 mg∙L−1 IBA for 10 min. For the rooting rate, the expected optimal treatment was 50 mg∙L−1 NAA and 40 mg∙L−1 IBA for 5–20 min. Finally, for bud germination, optimal treatments were 20 min of immersion in water, 30 mg∙L−1 6-BA plus 50 mg∙L−1 NAA for 15 min, and 30 mg∙L−1 6-BA for 5 min. Plantlet formation only occurred in the <one-year-old leaves, and at very low rates (maximum 5.8%); this outcome is likely attributable to the mother plant’s relatively old age (five years). Plantlet formation from cuttings is dependent on ensuring the rooting rate after callus initiation. Therefore, to promote rooting rates and bud germination, we recommend leaving more xylem at the base of leaf cuttings.

Effects of plant growth regulators and nitrogen on germination of Epimedium pseudowushanense after its stems and leaves reaped

In order to explore appropriate measures to promote germination after the harvest of Epimedium pseudowushanense, 6-BA, urea, ammonium bicarbonate and GA₃ were chosen to spray on the root and rhizomes, and then the biological indicators such as branches, leaf length, leaf width, plant height and so on, were measured in different periods, and the contents of epimedin A, epimedin B, epimedin C and icariin in the dry leaves were detected by HPLC. Results showed that 6-BA 90 mg·L⁻¹(B1), 6-BA 60 mg·L⁻¹(B2),6-BA 30 mg·L⁻¹+urea 300 mg·L⁻¹ (C1), 6-BA 60 mg·L⁻¹+urea 300 mg·L⁻¹(C2),6-BA 60 mg·L⁻¹+ ammonium bicarbonate 300 mg·L⁻¹(C4) significantly increased bud germination in the early period, and the plants quickly set up new system of photosynthesis, the branches in a month of which were higher than the control group respectively by 165.9%, 115.76%, 103.86%, 104.50%, 81.67%.However the branches developed the next year and the dry weight of leaves per plant in group B1 and B2 were much lower than that in control group. The groups that use 6-BA and nitrogen at the same time reaped a good yield of leaves even though the treatment had no significant influence on the branches developed the next year. The dry weight of leaves of C1, C2, C4 treatments were 36.80%, 32.84%, 45.97% more than the control group respectively. Therefore, C1, C2 and C4 treatments are the more appropriate to promote recovery after harvest. Furthermore, different groups, except 10 mg·L⁻¹ 6-BA treatment significantly reduced the content of epimedin C, other groups didn't have any significant effect on the contents of such flavonoids.

Growth performance in contrasting sets of mulberry ( Morus Spp.) genotypes explained by logistic and linear regression models using morphological and gas exchange parameters

Abstract Plant growth is key determinant for leaf yield and biomass accumulation in mulberry. Accurate prediction of yield ensures brushing of right quantum of silkworms for silk production. Repeated harvesting of leaves/shoots leads to stress with physiological and biochemical changes. This necessitates in-depth analysis of growth attributes leading to rejuvenation and biomass production. A total of 22 contrasting genotypes for growth (CSG) were shortlisted from a diverse set of germplasm based on Number of Days required for Bud Sprouting (NDBS), Shoot Elongation Rate (SER) and Number of Branches (NB) in two distinct seasons. The logistic regression analysis of CSG expressed in odds ratio showed positive regression coefficients for important traits viz., inter-nodal distance (2.71), NB (1.31), Total Shoot Length (TSL, 1.38), Length of the Longest Shoot (LLS, 1.17) and Number of Leaves on the Longest Shoot (NLLS, 1.18) for high growth in August 2016. The growth curve estimates for SER was significantly (P

Identification and functional analysis of germin-like protein Gene family in tea plant ( Camellia sinensis )

Germins and germin-like proteins (GLPs) are ubiquitious glycoproteins in the plant kingdom. They play critical roles in both plant development and responses to stresses. Here we report the identification and functional characterization of the GLP gene family in tea plant (Camellia sinensis). By mining the leaf transcriptomes of tea plants, eight genes encoding GLPs were identified, they were designated as CsGLP1-8. Phylogenetic analysis placed the eight CsGLPs into three subfamilies, with CsGLP4 and CsGLP3 in the subfamily I and II, respectively and all the rest in subfamily III. The functions of CsGLPs were further characterized at both biochemical and biological levels. Analysis of recombinant proteins produced by expressing full-length cDNAs of individual CsGLPs in E. coli revealed that all CsGLPs had oxalate oxidase (OxO) or superoxide dismutase (SOD) activities, which are considered as typical biochemical characteristics of GLPs. In addition, expression analysis of individual CsGLP genes during bud sprouting as well as under biotic and abiotic stresses further confirmed their involvements in tea plant development and stress response. In apical buds, CsGLP genes exhibited differential response to phenological changes. CsGLP2 increased more extremely at bud sprouting stage than dormant stage compared with other genes, signifying its potentiality as a bud germination marker for the selection of germplasms in tea breeding. Under drought and H2O2 stresses, the expression levels of CsGLP almost constantly down-regulated, suggesting that bud sprouting was suppressed by water shortage and oxidative stress. For biotic treatment, six genes showed obvious positive response to herbivore-induced damage. Especially, CsGLP1 and CsGLP2 were dramatically induced by geometrid feeding, indicating that these two GLP members may be involved in insect resistance in tea plant. The results of this study will help to better understand the function of GLPs family in tea plants and to further exploit this knowledge for tea breeding.

EFFECTS OF DIFFERENT GRAFTING METHODS AND TIMES ON GRAFTING SUCCESS AND PLANT DEVELOPMENT IN SARI ALIÇ HAWTHORN GENOTYPE (Crataegus azarolus L.)

The study was carried out to determine the different grafting methods and times on the grafting success and plant development in ‘Sarı Alıç’ hawthorn genotype (Crataegus azarolus L.) on Crataegus monogyna L. rootstock in Hatay province, eastern Mediterranean region of Turkey. T and chip budding and whip grafting methods were conducted on February 15, March 01, March 15, April 01, April 15, May 01 and May 15 dates in 2016. The grafting take and bud sprout percentages, graft shoot development and shoot diameter were also investigated. The results of the study showed that graft success and plant development were affected by grafting times and methods. The mean highest bud sprout percentage (71.91%) was found in whip grafting whereas mean graft shoot development (55.18 cm) and diameter (5.57 mm) were detected in T budding. The bud sprout ratio was the highest on April 01 and April 15 (84.44% and 77.77%, respectively). The results showed that whip grafting method applied within March and April months was very successful for growing of ‘Sarı Alıç’ hawthorn genotype in Hatay, Turkey ecological conditions.

扎龙湿地不同生境芦苇种群根茎数量特征及动态

PDF HTML阅读 XML下载 导出引用 引用提醒 扎龙湿地不同生境芦苇种群根茎数量特征及动态 DOI: 10.5846/stxb201703200469 作者: 作者单位: 齐齐哈尔大学 生命科学与农林学院,齐齐哈尔大学 生命科学与农林学院,齐齐哈尔大学 生命科学与农林学院,齐齐哈尔大学 生命科学与农林学院,东北师范大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31472134，31672471）；黑龙江省教育厅科学技术研究项目（12541887） Quantitative characteristics and dynamics of the rhizome of Phragmites australis populations in heterogeneous habitats in the Zhalong Wetland Author: Affiliation: College of Life Science and Agriculture,Forestry ,Qiqihar University,College of Life Science and Agriculture,Forestry ,Qiqihar University,College of Life Science and Agriculture,Forestry ,Qiqihar University,College of Life Science and Agriculture,Forestry ,Qiqihar University,Northeast Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:采用单位土体取样，计测长度和生物量的调查与统计方法，对扎龙湿地保护区4个生境芦苇种群根茎数量特征进行比较分析。结果表明，芦苇5月10日左右返青后进入营养生长期，根茎长度6-8月份缓慢增加，8-10月份显著增加，后期是前期的3.5-10.3倍，生长季中后期是种群新根茎补充和生长的主要时期，不仅实现了种群空间扩展，并为营养繁殖储备更多繁殖芽；根茎生物量和干物质贮量6-8月份逐渐减少，8-10月份又逐渐增加，均以生长季末期的10月份最大，并均显著地（P < 0.05）高于其他月份，种群根茎养分的消耗主要供给根茎芽的萌发和幼株生长，根茎养分的储藏又为翌年种群的更新及扩展提供物质保障，种群对地下根茎存在明显的养分"超补偿性"贮藏现象。种群根茎长度和生物量均以湿生生境最大，依次为旱生生境、水生生境，盐碱生境最小，根茎干物质贮量以旱生生境最大，依次为湿生生境、水生生境，盐碱生境最小。种群根茎长度与返青后实际生长时间之间均较好地符合直线函数关系，种群根茎生物量和干物质贮量与生长时间之间较好地符合二次曲线函数关系，R2在0.804-0.997之间，拟合方程均达到了显著或极显著（P < 0.01）水平。4个生境芦苇种群在根茎长度、生物量、干物质贮量等数量特征均表现出由遗传因素控制的比较稳定的季节动态规律，在生境间的差异及其差异序位又均基本稳定，均表现出明显的土壤因子环境效应，其中土壤含水量、有机质、速效氮为正向驱动，pH、速效磷为负向驱动，土壤含水量、pH对根茎数量特征的驱动作用更突出。 Abstract:A comparative study of the quantitative characteristics of the rhizome of Phragmites australis populations in four habitats in the Zhalong Wetland was performed by sampling a unit volume of soil and measuring biomass and rhizome length. The results showed that P. australis returned green around May 10 and began to enter the vegetative growth period. There was a slow increasing trend in rhizome length from June to August, but a significantly increasing trend was observed from August to October. Moreover, rhizome length in the late period was 3.5-10.3 times higher than that in the early period. The middle and late growth seasons were the main periods of new rhizome supplement and growth of the population, during which time the spatial expansion of the population was achieved and more breeding buds were reserved for nutritional reproduction. Rhizome biomass and dry matter storage decreased gradually from June to August, but increased gradually from August to October, with the largest biomass observed in October, the end of the growth season, and was significantly higher than in other months(P < 0.05). The consumption of rhizome nutrients in the population mainly contributed to the germination of rhizome buds and the growth of young plants. The storage of rhizome nutrients also provided material support for the renewal and expansion of the population in the next year. The phenomenon of "super compensatory" storage in the rhizomes of the population was obvious. The length and biomass of rhizomes were the largest in the wet habitat, followed by the xeric, and aquatic habitats, however, they were the lowest in the saline-alkali habitat. The dry matter storage of rhizomes was the largest in the xeric habitat, followed by the wet and aquatic habitats, it was the lowest in the saline-alkali habitat. There was a significant, linear correlation between rhizome length of P. australis and the actual growth time after returning green. However, there was a significant, logarithmic correlation between rhizome biomass, dry matter storage, and the actual growth time after returning green, the goodness of fit of equation was 0.804-0.997, and the fitting equation reached a significant level of P < 0.01. The length, biomass, and dry matter storage of P. australis rhizomes in the four habitats showed relatively stable seasonal dynamics controlled by genetic factors during the growing period. The differences between the habitats and their differential orders were basically stable, showing significant environmental effects of soil factors, among which, the soil water content, organic matter, and available nitrogen were the positive drivers, while pH and available phosphorus were the negative drivers. The driving effects of soil water content and pH were the most prominent. 参考文献 相似文献 引证文献

Effects of key growth conditions on endogenous hormone content in tillering stem bases, germination of lateral buds, and biomass allocation in Indocalamus decorus

Physiological responses and changes in growth of Indocalamus decorus Q.H.Dai under different ecological conditions are essential for further understanding growth regulation and adaptive mechanisms and establishing an evidence-based management system for optimal growth. In this study, the endogenous hormone content in tillering stem bases, germination of lateral buds, and biomass allocation of this bamboo species in different growth environments were investigated. Among the endogenous hormones in the basal stems of tillers, indole-3-pyruvic acid and zeatin riboside were highly correlated with lateral buds that germinated to form shoots, while gibberellic acid was highly correlated with lateral buds that germinated to form rhizomes. The best lateral bud germination characteristics were achieved with full sun, a density of six plantlets per pot, and watering every 6 days. I. decorus plantlets used different resource allocation strategies depending on treatment. Different ecological factors influenced endogenous hormones in the bamboo stem base, which affected lateral bud germination and biomass allocation.

The Impacts of Tumorigenic and Nontumorigenic Agrobacterium vitis Strains on Graft Strength and Growth of Grapevines.

The effects of tumorigenic and nontumorigenic strains of Agrobacterium vitis on graft strength and growth of grapevines was studied. A procedure was developed for inoculating graft interface surfaces with A. vitis and for measuring the force required to break grafts at different time points. Cuttings were soaked in an aqueous suspension of bacteria, about 106 CFU/ml, and bacteria were spread onto the graft interface during the grafting procedure. Tumorigenic strain CG49 caused reduced bud germination and increased callus (crown gall) at the graft union and at the base of cuttings at 30 days postinoculation (dpi) and significantly reduced shoot growth by 60 dpi whereas, at the same time points, nontumorigenic strain F2/5 inhibited callus formation but did not affect bud germination or shoot growth. Graft strength was enhanced at 30 dpi with CG49, presumably because the crown gall callus served to secure the union; graft strength was weakened by F2/5 over the same period. Between 30 and 60 dpi, the greatest increase in graft strength was observed in the water control. Following graft union inoculations, the A. vitis population increased more than 1,000-fold within 5 days.

Comprehensive Analysis of the Cork Oak (Quercus suber) Transcriptome Involved in the Regulation of Bud Sprouting

Cork oaks show a high capacity of bud sprouting as a response to injury, which is important for species survival when dealing with external factors, such as drought or fires. The characterization of the cork oak transcriptome involved in the different stages of bud sprouting is essential to understanding the mechanisms involved in these processes. In this study, the transcriptional profile of different stages of bud sprouting, namely (1) dormant bud and (2) bud swollen, vs. (3) red bud and (4) open bud, was analyzed in trees growing under natural conditions. The transcriptome analysis indicated the involvement of genes related with energy production (linking the TCA (tricarboxylic acid) cycle and the electron transport system), hormonal regulation, water status, and synthesis of polysaccharides. These results pinpoint the different mechanisms involved in the early and later stages of bud sprouting. Furthermore, some genes, which are involved in bud development and conserved between species, were also identified at the transcriptional level. This study provides the first set of results that will be useful for the discovery of genes related with the mechanisms regulating bud sprouting in cork oak.

Response of Silixol Sugarcane to Growth and Physio-Biochemical Characteristics of Sugarcane

Field experiment was conducted during spring season to study the effect of Silixol Sugarcane on growth, yield and juice quality attributes of sugarcane. Treatments comprised two sets with three doses of Silixol @ 2 ml, 4 ml and 8 ml/l of water: Set I—application was done at five critical stages of growth and Set II—Silixol was applied in every month till maturity. Application of Silixol Sugarcane improved bud germination with increasing dose, highest being @ 4 ml/l. Higher specific leaf weight was observed in treated plants as compared to control. Silixol Sugarcane application showed improvement in plant height at various growth stages, being highest at grand growth stage. Dry matter partitioning in leaf, stalk, leaf sheath and root tissues indicates that Silixol Sugarcane application has positive effect on physiological processes. At grand growth stage, maximum dry matter accumulation was recorded in stalks of all treatments. Activity of nitrate reductase, an indispensible enzyme for nitrogen metabolism, in leaves is improved by Silixol application. Silicon content determined in leaf tissues increased with an increase in the Silixol level; highest was obtained with 8 ml/l, and lowest was in control. Silixol Sugarcane application had a positive impact on cane yield attributes viz., cane length and girth, which contributed to more cane yield. Juice quality attributes viz., Brix, juice purity, sucrose, CCS% juice, were relatively better in treated canes. Monthly application of Silixol even at higher dose has no negative impact on plant growth and yield, indicating that the formulation is completely safe. Findings of the present study indicated that applications of Silixol Sugarcane @ 4 ml/l at five critical stages could lead to a yield increment up to 20%.

Optimization of hormone combinations for root growth and bud germination in Chinese fir (Cunninghamia lanceolata) clone leaf cuttings

In order to ascertain the optimal hormone combination for Chinese fir (Cunninghamia lanceolata) leaf cuttings, an L16(4)4 orthogonal test of 6-benzylaminopurine (6-BA), 1-naphthaleneacetic acid (NAA), and indole-3-butyric acid (IBA) (0, 10, 30, or 50 mg · L−1 of each exogenous hormone) immersion for 5, 10, 15, or 20 min was conducted. Callus initiation rate and rooting promotion rate were mainly affected by treatment time, root length increase by 6-BA concentration, and bud germination rate and plantlet formation rate by NAA concentration. The expected optimal combination for callus initiation rate was 50 mg · L−1 6-BA + 0 mg · L−1 NAA + 30 mg · L−1 IBA + 10 min; for rooting promotion rate, it was 0–10 mg · L−1 6-BA + 10 mg · L−1 NAA + 30 mg · L−1 IBA + 20 min; for bud germination rate, it was 50 mg · L−1 6-BA + 0–10 mg · L−1 NAA + 0–30 mg · L−1 IBA + 20 min; and for seedling formation rate for No. 4, it was 10 mg · L−1 6-BA + 10 mg · L−1 NAA + 0 mg · L−1 IBA + 20 min. Light microscopy image analysis revealed that a cluster of primordial cells was produced 40 days after cutting, and mastoid cells developed into peninsula cells in calli that were cultured for 50 days.

Extraction of Total Protein from Axillary Buds of Sugarcane (Saccharum spp.) for Proteomic Analysis

Since sugar cane production depends on the germination of axillary buds, the analysis of the products of gene expression in axillary buds from different sugarcane varieties (Saccharum spp.) in each growth cycle is important to reveal the proteins related to sprouting potential for crop renovation and consequent increase in sugarcane production. Current study has employed a simple method for protein extraction from axillary buds of RB867515, RB866928 and CTC04 sugarcane varieties to obtain protein fractions for two-dimensional electrophoresis and proteomic analysis. The TCA/acetone method for protein extraction with modifications in the centrifugation processes and in the incubation time of samples revealed a large number of well-defined bands in SDS-PAGE system with molecular weights ranging between 120 and 10 kDa. The evidence that the method TCA/acetone modified (1) by using 200 mg of tissue axillary buds; (2) by inclusion of an incubation step at room temperature for 20 min under stirring; (3) by aliquots division for a better recovery from the supernatant; (4) by the absence of phenol in one extraction phase; and (5) by the increase in centrifugal rotation from 12,000×g to 13,860×g and an increase from 15 to 30 min centrifugation time (in the precipitation and wash steps) was more efficient than the other methods used for sugarcane, is one more example showing that methods for extracting proteins in plants are specific to different tissues.

Use of artificially-induced freezing temperatures to identify freeze tolerance in above-ground buds of Saccharum and Erianthus accessions

Sugarcane is a crop which is primarily grown between 30°N and 30°S latitude in tropical environments. Small areas of production in sub-tropical regions exist, and there is an increasing desire to produce the crop in colder environments. Cold-tolerant sugarcane is important both to the sub-tropical sugarcane industries and potential biofuels producers who seek to use sugarcane as a feedstock. Selection for this trait under natural conditions is difficult in sugarcane growing regions because damaging freezes are sporadic. The objective of this study was to identify sugarcane accessions for use in introgression breeding which have above-ground buds that are tolerant to freezing conditions. Above-ground (stalk) buds of 63 Saccharum, and 4 Erianthus accessions were frozen for 6 days at −7 °C, and germinated buds were counted three weeks post-treatment. Accessions which had more bud cold tolerance than the Louisiana commercial cultivar ‘L 97-128’ were MPTH97-213, SES114, Guangxi87-22 and SES234A. Heritability estimates for percent reduction in bud germination and height of the shoots following freeze treatment was 0.47 and 0.49, respectively. Identified clones will be used in future breeding efforts at the United States Department of Agriculture, Agricultural Research Service, Sugarcane Research Unit in Houma, LA, USA.

不同施肥处理对铁皮石斛生长及产量的影响

为明确不同肥料对铁皮石斛生长及产量的影响，以蚕沙、羊粪、牛粪及菜籽饼等为主要原料开展了铁皮石斛盆栽效果试验。结果表明，与对照(控释化肥)相比，蚕沙有机肥、羊粪菜饼复合有机肥及羊粪牛粪羽毛粉复合有机肥等处理对铁皮石斛新芽萌发、新芽长度均表现出了明显的促进作用,铁皮石斛生物量增加显著。 In order to clarify the effect of different fertilizers on the growth and yield of Dendrobium offici-nale, the pot experiment of Dendrobium officinale was carried out with silkworm excrement, sheep manure, cow dung and rapeseed cake as the main raw materials. The results showed that compared with the control, the organic matter of silkworm excrement, the compound organic fertilizer of rapeseed cake and sheep manure, the compound organic fertilizer of sheep manure, cow dung and feather powder could improve the germination of new buds, the length of shoots, and the biomass of Dendrobium officinale increased significantly.

Standardization of grafting technique in litchi

The present experiment was conducted at the Research Centre, Ranchi of the ICAR Research Complex for Eastern Region, during the period from June, 2015 to December, 2016 to investigate the effect of girdling and defoliation of scion shoot on the success and growth of grafts in litchi cv. Shahi. The branches were girdled (removing of 3 mm ring from branches of 40–50 mm girth) one month before the collection of scion sticks for grafting. Defoliation was performed 7 days before the collection of scionsticks. Wedge grafting was performed under shadenet with temperature ranging from 26–32°C and RH 70–80%. The graft take success and vegetative growth were markedly improved as a result of girdling and defoliation. Among the different treatments, the minimum time required for bud sprout (15.40 days), highest scion height (24.25 cm), scion girth (7.14 mm), number of sprouts per graft (2.64), sprout length (4.80 cm), number of compound leaves (8.34), rachis length (9.33 cm), leaflet length (9.37 cm), leaflet width (3.37 cm) and graft success (56.43%) were observed in girdling + defoliation treatment. Scion which had higher girth after grafting was positively correlated with the number of compound leaves, leaflet length and leaflet width. The highest graft success rate (70.83%) was recorded during July. Hence, it was concluded that girdling of branches on scion varieties, one month prior to collection of scionstick and defoliation atleast 7 days before the collection, can enhance the success rate of grafting and plant growth of grafts in litchi.

In-vitro protocol for mass multiplication in bougainvillea (Bougainvillea sp) cv. Mahatma Gandhi and Refulgens

Bougainvillea (Bougainvillea sp) is recognized as a high value landscape plant. It is usually propagated by hardwood cuttings, but in certain varieties, rooting per cent is very low, ultimately the rate of multiplication is less. Therefore, the present investigation was carried with an objective to standardize the protocol for quick, easy and mass multiplication of two difficult-to-root cultivars Mahatma Gandhi and Refulgens, using in vitro techniques. Nodal sections with axillary buds were excised, surface-sterilized and cultured on MS medium supplemented with plant growth regulators. Pre-treatment agitation of explants in carbendazim (0.1%) + Metalaxyl (0.1%) + 8-HQC (200 mg/l) for 3 hr followed by quick dip in ethyl alcohol (70%; v/v) for 30 sec and surface sterilization in HgCl2 (0.1%) for 5 min was used for reducing contamination. MS medium with BAP (5 mg/l) was found to be the best with highest percentage of culture establishment (81.13) and the fastest bud sprout (8.18 days). MS medium supplemented with BAP (4.0 mg/l) and kinetin (0.5 mg/l) resulted in highest shoot proliferation in both the cultivars. The best treatment for micro-shoot elongation was the one where MS medium was supplemented with 0.5 mg/l GA3 giving the highest elongation (3.89 cm). In vitro rooting of micro-shoots was done in half-strength MS medium supplemented with 1.0 mg/l IBA. Hardening was done in glass jar with polypropylene cap.