scholarly journals Pruning Responses of Tissue-Cultured Plantlets of Rhododendrons

1989 ◽  
Vol 7 (1) ◽  
pp. 23-25
Author(s):  
Virginia I. Lohr ◽  
Andrew B. Sudkamp

Abstract Plantlets of Rhododendron ‘Molly Ann’, R. ‘Paprika Spiced’, and R. ‘Travis L.’, recently rooted from tissue culture, were grown in a greenhouse in individual containers. Plants pruned by pinching, top-pruning, or root-pruning were compared to unpruned plants. Growth, as measured by shoot height, shoot dry weight, root dry weight, and stem caliper, was generally reduced by pruning. Top-pruning and pinching induced branching in all cultivars tested and improved stem taper (ratio of basal to upper caliper) in two cultivars, including R ‘Travis L.’, which is particularly prone to develop weak stems when produced by tissue culture.

HortScience ◽  
2011 ◽  
Vol 46 (9) ◽  
pp. 1303-1307 ◽  
Author(s):  
Genhua Niu ◽  
Denise Rodriguez ◽  
Mengmeng Gu

Texas mountain laurel (Sophora secundiflora) is a native shrub tolerating drought, heat, windy conditions, and alkaline or wet soils. However, its availability is somewhat low and little information is available on nutrient requirement and other culture information. Two greenhouse experiments were conducted to quantify the responses of Texas mountain laurel to different forms and rates of nitrogen (N) fertilizer. In Expt. 1, 1-year old seedlings were treated for 194 days with three NO3:NH4 ratios at 25:75, 50:50, and 75:25 and two rates of N at 100 and 200 mg·L−1 in a factorial design. There was no interaction between the N rate and form on any growth parameters. Nitrogen form did not significantly affect shoot dry weight, root dry weight, root–to-shoot ratio, or the total dry weight. There was no significant difference between N rate of 100 and 200 mg·L−1 on root dry weight, root-to-shoot ratio, or the total dry weight. The shoot dry weight of Texas mountain laurel fertilized with 100 mg·L−1 was higher compared with that of the plants fertilized at 200 mg·L−1. The reduced shoot dry weight at N of 200 mg·L−1 was the result of the higher substrate salinity. In Expt. 2, seedlings were fertilized with five N rates (50, 100, 150, 200, and 250 mg·L−1) for 203 days. Plants watered with 150, 200, and 250 mg·L−1 were taller than those fertilized with 50 mg·L−1. The shoot height of plants watered with 100 mg·L−1 was only significantly different from 50 mg·L−1. For rapid growth of Texas mountain laurel, a N rate range of ≈150 mg·L−1 was recommended supplied with a combination of NO3-N and NH4-N in the ratios of 0.3 to 3.0.


Author(s):  
Mir Jannatul Mawa ◽  
Md. Ashraful Haque ◽  
Mohammad Mehfuz Hasan Saikat ◽  
Shah Mohammad Naimul Islam

Aims: To screen potato genotypes for salt tolerance using in vitro salt stress and moleulcar markers. Experimental Design: The experiment was arranged in Completely Randomized Design (CRD) with three replications. Place of the Study: The experiment was conducted at the Molecular Biology and Tissue Culture Laboratories, Institute of Biotechnology and Genetic Engineering, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh. Methodology: In vitro screening of five potato genotypes (CIP 112, CIP 117, CIP 120, CIP 127, and CIP 128) was done in an agar medium using tissue culture technique at different concentrations of salt viz. 0.0, 10, 20, 40, 60, 80, 100, 120 mM of NaCl. All genotypes were further analysed through SSR markers using three primers. The DNA bands were visualized on gel electrophoresis and scored for polymorphic loci, gene diversity, and genetic distance. NTSYSpc program was used for constructing  unrooted neighbor-joining tree and scatter diagram. Results: Potato genotypes CIP 112 and CIP 117 emerged as the most salt tolerant genotypes with the highest plant height, shoot dry weight, root length, and root dry weight at different concentrations of NaCl. CIP 127 and CIP 128 were poorly tolerant to salt stress. The most sensitive genotype CIP 120 produced minimum plant height, shoot dry weight, root length, and root dry weight at different NaCl concentrations. Results indicated that significant differences were found among cultivars. The banding pattern of microsatellite confirmed a distinct polymorphism among salt tolerant, moderately salt tolerant and salt sensitive lines. The clustering pattern of the potato genotypes suggests that variations occur due to genotypic variation and possibly not epigenetic adaptation under salt stress conditions. Conclusion: The salt tolerant pototo genotypes CIP 112 and CIP 117 can be used for developing salt tolerant genotypes.


2016 ◽  
Vol 38 (2) ◽  
Author(s):  
MARCUS VINICIUS SANDOVAL PAIXÃO ◽  
JOSÉ CARLOS LOPES ◽  
EDILSON ROMAIS SCHMILDT ◽  
RODRIGO SOBREIRA ALEXANDRE ◽  
CAROLINE MERLO MENEGHELLI

ABSTRACT This study aimed to evaluate the potential of multi-stems in avocado seeds according to their mass as well as the adventitious rooting of multi-stem budding with or without the use of auxin. The research was carried out at the Vegetation House of Federal Institute of Espírito Santo, Campus Santa Teresa -ES, with seeds of different masses: <60 g, 61 to 80 g, 81 to 100 g and >100 g, in which each experimental unit was made of five seeds, distributed within five repetitions, under a completely randomized design. The seeds were put to germinate and the percentage number of emergence and multiple stems were evaluated. After 150 days, the following evaluations were carried out: survival of rooted cuttings; number of leaves; stem diameter; root length; root volume; root and shoot fresh mass; root and shoot dry mass; shoot height; absolute growth and shoot growth rate; shoot dry weight/root dry mass ratio; shoot height/stem diameter ratio; shoot height/root length and Dickson's quality index ratio. Avocado seeds with mass over 100 g and between 81-100 g presented higher percentage of multiple stems. Rods over 20 cm that were not treated with IBA (indole-3-butyric acid) resulted on avocado plants of better quality. The use of IBA (2000 mg L-1) does not affect the rooting and growth of avocado's multi-stem plants.


2014 ◽  
Vol 23 (3) ◽  
pp. 236-245 ◽  
Author(s):  
Mauritz Vilhelm Vestberg ◽  
Sanna Kukkonen ◽  
Päivi Parikka ◽  
Dan Yu ◽  
Martin Romantschuk

There is increasing global interest in using compost to suppress soil-borne fungal and bacterial diseases and nematodes. We studied the reproducibility of compost suppressive capacity (SC) against Pythium wilt of cucumber using nine composts produced by the same composting plant in 2008 and 2009. A bioassay was set up in a greenhouse using cucumber inoculated with two strains of Pythium. The composts were used as 20% mixtures (v:v) of a basic steam-sterilized light Sphagnum peat and sand (3:1, v:v). Shoot height was measured weekly during the 5-week experiment. At harvest, the SC was calculated as the % difference in shoot dry weight (DW) between non-inoculated and inoculated cucumbers. The SC was not affected by year of production (2008 or 2009), indicating reproducibility of SC when the raw materials and the composting method are not changed. Differences in shoot height were not as pronounced as those for shoot DW. The results were encouraging, but further studies are still needed for producing compost with guaranteed suppressiveness properties.


2001 ◽  
Vol 19 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Wallace G. Pill ◽  
James A. Gunter

Abstract This study was conducted to determine whether treating seeds of ‘Sensation Mixed’ cosmos (Cosmos bipinnatus Cav.) and ‘Bonanza Gold’ marigold (Tagetes patula L.) with paclobutrazol (PB) could suppress seedling growth. Seeds were soaked in solutions of 0, 500 or 1000 mg PB/liter (ppm PB) for 16 hours at 25C (77F) or they were primed [−0.5 MPa (−5 bars) for 7 days at 20C (68F)] in Grade 5 exfoliated vermiculite moistened with 0, 500 or 1000 ppm PB solltuions. Soaked and primed seeds were dried for 1 day at 19C (65F) and 25% relative humidity. These seeds and control (non-treated) seeds were sown into plug cells containing peat-lite. Increasing PB concentration decreased cosmos shoot height at 32 days after planting (DAP), but decreased emergence percentage, responses that were more pronounced with priming than with soaking. A 1 ppm PB growth medium drench [30 ml/cell(0.2 mg PB/cell)] and, to a greater extent a 10 mg PB/liter (ppm PB) shoot spray [2 ml/shoot (0.02 mg PB/shoot)], both applied at 10 DAP, resulted in greater cosmos shoot height suppression at 32 DAP than treatment of seeds with 1000 ppm PB. Soaking marigold seeds in 1000 ppm PB failed to decrease shoot height below those of plants from non-treated seeds at 32 DAP. However, exposure to 1000 ppm PB during priming of marigold seeds resulted in a similar shoot height suppression (13%) as the growth medium drench, and similar shoot dry weight reduction (21%) as the shoot spray. Suppression of shoot growth by this seed treatment was short-term since by five weeks after transplanting into 15 cm (6 in) pots, only marigold plants that had received the growth medium drench or shoot spray were smaller than those of control plants. Treating marigold seeds with 1000 mg ppm PB used about one-fifth the PB used to drench the growth medium.


1989 ◽  
Vol 40 (2) ◽  
pp. 293 ◽  
Author(s):  
DR Eagling ◽  
RJ Sward ◽  
GM Halloran

Measurements were made on the effect of barley yellow dwarf virus (BYDV) infection on the early growth of four commercial cultivars of ryegrass (Lolium spp.) under two different temperatures (24�C and 16�C). At 24'C, BYDV infection was associated with reduced root dry weight (30-40%) in all cultivars; the effect of infection on shoot dry weight and leaf area was variable. At 16�C, the effect of BYDV infection was variable, being associated with increases in root dry weight, shoot dry weight, and leaf area in one cultivar (Grasslands Ariki) and decreases in another (Victorian). In two other cultivars, root dry weight, shoot dry weight and leaf area were not significantly affected (P>0.05) by infection with BYDV.At 24�C, the reductions in root dry weight associated with BYDV infection were not concomitant with reductions in the root relative growth rates. Up to at least 28 days after inoculation (46-50 days after germination) reductions in root dry weight were associated with both aphid-feeding damage and virus infection. Experiments with the cultivar Victorian, showed that shoot dry weight was not significantly affected (P>0.05) by feeding with viruliferous (BYDV) or non-viruliferous aphids (Rhopalosiphum padi L.). At 16�C, changes in root and shoot dry weight were associated with changes in the root and shoot relative growth rates.


Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 489-493 ◽  
Author(s):  
Frank L. Young ◽  
David R. Gealy ◽  
Larry A. Morrow

In the greenhouse, glyphosate [N-(phosphonomethyl)glycine] at 0.6 kg ae/ha applied directly to seeds alone or seeds on the soil surface reduced germination and shoot dry weight of common rye (Secale cerealeL. ♯3SECCE). Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) applied similarly at 0.6 kg ai/ha reduced germination and shoot dry weight of downy brome (Bromus tectorumL. ♯ BROTE) and wheat (Triticum aestivumL. ‘Daws' ♯ TRZAX). Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5 (4H)-one] at 0.6 kg ai/ha applied to seeds, soil, or seeds and soil had very little effect on germination, but significantly reduced shoot dry weight of common rye, downy brome, wheat, and jointed goatgrass (Aegilops cylindricaHost. ♯ AEGCY). Pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide] at 0.6 kg ai/ha, and propham (isopropyl carbanilate) at 3.4 kg ai/ha plus extender (p-chlorophenyl-N-methylcarbamate) at 0.4 kg ai/ha substantially reduced shoot height and dry weight of all species, regardless of application method, with pronamide completely inhibiting shoot elongation and dry-weight production in three of the four species.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ricksy Prematuri ◽  
Maman Turjaman ◽  
Takumi Sato ◽  
Keitaro Tawaraya

Opencast nickel mining is common in natural forests of Indonesia. However, rehabilitation of postmining degraded land is difficult. We investigated the effect of opencast nickel mining on soil chemical properties and the growth of two fast-growing tropical tree species, Falcataria moluccana and Albizia saman. Soil was collected from post-nickel mining land and a nearby natural forest. Soil pH, available phosphorus (P) concentration, total carbon (TC) and total nitrogen (TN) concentration, C/N ratio, cation exchange capacity (CEC), and exchangeable K, Na, Mg, Ca, Fe, and Ni concentrations were determined. Falcataria moluccana and A. saman were then grown in the collected soils for 15 weeks in a greenhouse. Shoot height and shoot and root dry weights of the seedlings were measured. The post--nickel mining soils TN, TC, available P, CEC, and exchangeable Ca and Na concentrations decreased by 98%, 93%, 11%, 62%, 85%, and 74%, respectively, in comparison with the natural forest soils. The pH of postmining soil was higher than natural forest soil. Shoot dry weight of F. moluccana seedlings grown in postmining soil was significantly ( P < 0.05 ) lower than that of seedlings grown in natural forest soil. However, there was no difference in shoot dry weight between A. saman seedlings grown in natural forest soil and postmining soil, as well as root dry weights of both species. The results indicate that opencast nickel mining decreased soil fertility, which subsequently inhibited the growth of F. moluccana and A. saman seedlings.


HortScience ◽  
2018 ◽  
Vol 53 (6) ◽  
pp. 795-798 ◽  
Author(s):  
Chang-Tsern Chen ◽  
Ching-Lung Lee ◽  
Der-Ming Yeh

Growth and photosynthetic parameters were measured in Eustoma grandiflorum (Raf.) Shinn. ‘Umihonoka’ grown hydroponically under nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), or magnesium (Mg) deficiency in 1/2 strength of modified Johnson’s solution. Plant height, node number, and leaf area were all reduced under N, P, K, and Ca deficiencies but not under Mg deficiency as compared with plants grown in the complete nutrient solution. Shoot and root dry weight were reduced in the N-, P-, K-, and Ca-deficient treatments, whereas root but not shoot dry weight was lowered by Mg-deficient treatment. Shoot-to-root dry weight ratio decreased under N and P deficiencies, increased under K and Mg deficiency, but was not altered under Ca deficiency. Decreased net photosynthetic rate (Pn) of N-, P-, and K-deficient leaves was all related to lower stomatal conductance (gS), whereas N-deficient leaves also accompanied by a higher intercellular carbon dioxide concentration (Ci). The Mg-deficient treatment did not alter chlorophyll fluorescence Fv/Fm, maximal fluorescence (Fm), or minimal fluorescence (Fo). Decreased Fv/Fm of N-, P-, K-, and Ca-deficient leaves was all related to lower Fm, whereas N- and P-deficient leaves also accompanied by lower Fo. A key was developed for the identification of N, P, K, Ca, and Mg deficiency symptoms.


2013 ◽  
Vol 1 (4) ◽  
pp. 228-232 ◽  
Author(s):  
P. K. Roy ◽  
M. A. R. Sarkar ◽  
S. K. Paul ◽  
A. Dey

An experiment was conducted at the Seed Laboratory of the Department of Agronomy, Bangladesh Agricultural University, Mymensingh during the period from January to April 2012 to study the effect of osmopriming of Boro rice seed (cv. BRRI dhan29). Seeds were soaked in 1%, 3% and 5% solutions of ZnSO4, KCl and CaCl2 for 24 hours, respectively, with 30 hours incubation at 35°C temperature. Seed quality tests such as percent germination, mean germination time, vigor index, shoot length, root length, shoot dry weight and root dry weight of rice seedlings were measured for all treatments. Population m-2 was also calculated to investigate the field establishment of primed seeds. The highest germination, vigor index, population m-2, shoot length and shoot dry weight at 15 and 30 DAS, root length at 15 DAS, root dry weight at 15 and 30 DAS and the lowest mean germination time was observed from priming of seeds with 3% ZnSO4. Exceptionally, priming with 3% CaCl2 showed the highest root length at 30 DAS. On the contrary, 3% and 5% CaCl2 priming treatment showed the lowest germination, vigor index, population m-2, shoot length and shoot dry weight at 15 and 30 DAS, root length at 15 DAS, root dry weight at 15 and 30 DAS and the highest mean germination time. It can be concluded that rice seed (cv. BRRI dhan29) can be primed with 3% ZnSO4 solution for improving germination and field establishment of rice seedlings.DOI: http://dx.doi.org/10.3126/ijasbt.v1i4.9131  Int J Appl Sci Biotechnol, Vol. 1(4): 228-232


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