scholarly journals Developmental Stage and Growth Regulator Concentration Differentially Affect Vegetative Propagation of Select Clones of Taxodium Rich.

HortScience ◽  
2012 ◽  
Vol 47 (2) ◽  
pp. 238-248 ◽  
Author(s):  
Andrew R. King ◽  
Michael A. Arnold ◽  
Douglas F. Welsh ◽  
W. Todd Watson

In previous studies, baldcypress [Taxodium distichum (L.) Rich.] clones were selected for improved field tolerance to alkaline soils, drought, foliar or soil salinity exposure, and for ornamental traits. Objectives of the current research were to 1) determine the clonal responses to potassium salt of indole-3-butyric acid (K-IBA) across seasonal developmental stages of cuttings; and 2) to determine whether rooting and callus percentages and rooted cutting quality (root number, length, and mass) would be sufficient for commercial production should these clones be released to industry. Cuttings were taken from 24 clones at three distinct stages of stem maturity (softwood, semihardwood, and hardwood). Three concentrations of K-IBA were tested [0, 7,500, and 15,000 mg·L−1 (0, 31.1, 62.2 mm, respectively)] on each clone at each stage. Rooting percentages ranged from ≈94% (clone MX1MC33) at the softwood stage to 0% for several clones at the hardwood stage. Some clones such as MX5MC17 rooted at statistically similar percentages in the softwood and semihardwood stages (88% and 83%, respectively). Clone EP3DC16 rooted at low levels (less than 20%) in all stages. Significant (P ≤ 0.05) interactions occurred between growth stage and clone in some cases. Clone EP8DC14 rooted at 59% at the softwood stage but only 37% at the semihardwood stage. Root number and length exhibited three-way interactions (P ≤ 0.05) among clone, developmental stage, and K-IBA concentration. Mean total root length ranged from 2 cm per cutting on semihardwood cuttings of MX2MC31 treated with no growth regulator to 81 cm per cutting on softwood cuttings of TX8DC38 treated with 7500 mg·L−1 K-IBA. Mean root length varied from 2 cm for several clones at the semihardwood stage to 11 cm for softwood cuttings of MX2MC31 treated with 15,000 mg·L−1 K-IBA. The greatest rooting percentages across K-IBA concentrations were typically at the softwood stage. Cuttings treated with either 7,500 or 15,000 mg·L−1 K-IBA rooted at the greatest percentages across stem maturity stages. No clone rooted well in the hardwood stage. The high concentration of K-IBA (15,000 mg·L−1) sometimes induced basal stem damage.

1999 ◽  
Vol 17 (3) ◽  
pp. 123-125
Author(s):  
Jason J. Griffin ◽  
Frank A. Blazich ◽  
Thomas G. Ranney

Abstract Shoot tip cuttings of Quercus phillyraeoides A. Gray ‘Emerald Sentinel’ (‘Emerald Sentinel’ oak), in a transitional growth stage between softwood and semi-hardwood, were collected from containerized plants growing under uniform fertility on June 4, 1998. Cuttings were treated with talc formulations of indolebutyric acid (IBA), ranging from 0 to 8000 ppm (0.8%), and placed under intermittent mist with shade levels excluding 0%, 30%, 60% or 90% of full solar irradiance. After 14 weeks, percent rooting averaged 18% and was unaffected by either IBA concentration or shading regime. Similarly, both mean root number per rooted cutting and mean root length were unaffected by IBA concentration or shading. Roots per rooted cutting and mean root length averaged 2.6 and 41 mm (1.6 in), respectively. Results suggest that shading stem cuttings of ‘Emerald Sentinel’ during propagation does not affect rooting.


HortScience ◽  
2011 ◽  
Vol 46 (10) ◽  
pp. 1387-1393
Author(s):  
Andrew R. King ◽  
Michael A. Arnold ◽  
Douglas F. Welsh ◽  
W. Todd Watson

In previous studies, baldcypress [Taxodium distichum (L.) Rich.] clones were selected for tolerance to high pH soils, drought and salt exposures, and ornamental characteristics. The objective of the current research was to determine the treatment combinations that yielded optimum root quantity (percentage) and rooted cutting quality (root number, length, dry mass, and shoot dry mass) on vegetative cuttings for a representative clone. Cuttings were treated with factorial combinations of one of four potassium salt of indole-3-butyric acid (K-IBA) concentrations [0, 5,000, 10,000, 15,000 mg·L−1 (0, 20.72, 41.44, 62.16 mm, respectively)], wounded or not wounded (1-cm long basal incision), and rooted in one of three substrates (100% perlite, 100% peatmoss, or 50% perlite:50% peatmoss). Data indicated a tradeoff between potential rooting quantity and root quality measurements in response to different substrates. Although rooting percentages were affected by substrates only at P ≤ 0.10 (53% in 100% perlite versus 36% in 100% peatmoss), there were highly significant (P ≤ 0.0001) differences in rooted cutting potential among substrates as measured by the percentage of cuttings with basal callus. Cuttings placed in 100% perlite callused at 85%, whereas cuttings placed in 100% peatmoss callused at ≈53%. The 100% peatmoss treatment, however, yielded cuttings with significantly greater root quality for all measurements, except root number per cutting. Wounding cuttings proved to have deleterious effects on root quality measurements. Total root length was ≈14.5 cm for non-wounded cuttings and ≈10.8 cm for wounded cuttings. Increasing K-IBA concentrations did not significantly (P ≤ 0.05) affect rooting or callus percentages but did significantly affect root dry mass, total root length, and average root length per cutting. Total root length increased from 10.8 cm at 0 mg·L−1 K-IBA to 16 cm at 15,000 mg·L−1 K-IBA. Mean root number per cutting increased from ≈1.6 with wounded cuttings planted in 100% peatmoss to ≈3.1 with non-wounded cuttings planted in 100% perlite. Results suggested that high-quality softwood baldcypress cuttings should not be wounded, should be treated with 15,000 mg·L−1 K-IBA, and grown in a substrate with intermediate water-holding capacity to achieve an acceptable balance between rooting percentage and rooted cutting quality objectives.


2016 ◽  
Vol 87 (4) ◽  
pp. 570-575
Author(s):  
Mariana Roennau Lemos Rinaldi ◽  
Eduardo Martinelli de Lima ◽  
Luciane Macedo de Menezes ◽  
Susana Maria Deon Rizzatto ◽  
Paulo Ricardo Baccarin Matje ◽  
...  

ABSTRACT Objective: To evaluate and compare the eruption rates of lower second premolars (LPm2) at different developmental stages using cone-beam computed tomography (CBCT). Materials and Methods: Retrospectively, 31 individuals (9.77 ± 1.25 years) had their LPm2 scored according to the Demirjian method, and afterwards they were split into three groups according to developmental stage, as follows: D = complete-formed crowns; E = root length less than crown height; and F = root length greater than or equal to crown height. Linear distances from the LPm2 crown tip to the anatomical reference line (ARL) and to the occlusal plane line (OPL) were measured in paired CBCT scans (T1, T2), taken with an average interval of 8.6 months between them. Eruption rates (mm/y) were calculated and then compared between groups. Results: Eruption rates were greater for LPm2 at stage F than at stages D or E (P < .01) regardless of whether they were measured from the ARL (D = 2.84 mm/y; E = 2.55 mm/y; F = 5.38 mm/y) or from the OPL (D = 1.82 mm/y; E = 2.02 mm/y; F = 5.26 mm/y). Eruption rates evaluated from the ARL and the OPL had no statistically significant differences (P = .052), and a positive correlation (r = .79, P < .001) between them was observed. Conclusions: LPm2 at Demirjian stage F showed greater eruption rates than at stages D or E, regardless of whether rates were measured from the ARL or the OPL. Faster eruption is expected for LPm2 at stage F. Evaluation of the LPm2's developmental stage using CBCT can aid in clinical decision making regarding the correct timing for intervention.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuping Li ◽  
Xiaoju Liang ◽  
Xuguo Zhou ◽  
Yu An ◽  
Ming Li ◽  
...  

AbstractGlycyrrhiza, a genus of perennial medicinal herbs, has been traditionally used to treat human diseases, including respiratory disorders. Functional analysis of genes involved in the synthesis, accumulation, and degradation of bioactive compounds in these medicinal plants requires accurate measurement of their expression profiles. Reverse transcription quantitative real-time PCR (RT-qPCR) is a primary tool, which requires stably expressed reference genes to serve as the internal references to normalize the target gene expression. In this study, the stability of 14 candidate reference genes from the two congeneric species G. uralensis and G. inflata, including ACT, CAC, CYP, DNAJ, DREB, EF1, RAN, TIF1, TUB, UBC2, ABCC2, COPS3, CS, R3HDM2, were evaluated across different tissues and throughout various developmental stages. More importantly, we investigated the impact of interactions between tissue and developmental stage on the performance of candidate reference genes. Four algorithms, including geNorm, NormFinder, BestKeeper, and Delta Ct, were used to analyze the expression stability and RefFinder, a comprehensive software, provided the final recommendation. Based on previous research and our preliminary data, we hypothesized that internal references for spatio-temporal gene expression are different from the reference genes suited for individual factors. In G. uralensis, the top three most stable reference genes across different tissues were R3HDM2, CAC and TUB, while CAC, CYP and ABCC2 were most suited for different developmental stages. CAC is the only candidate recommended for both biotic factors, which is reflected in the stability ranking for the spatio (tissue)-temporal (developmental stage) interactions (CAC, R3HDM2 and DNAJ). Similarly, in G. inflata, COPS3, R3HDM2 and DREB were selected for tissues, while RAN, COPS3 and CS were recommended for developmental stages. For the tissue-developmental stage interactions, COPS3, DREB and ABCC2 were the most suited reference genes. In both species, only one of the top three candidates was shared between the individual factors and their interactions, specifically, CAC in G. uralensis and COPS3 in G. inflata, which supports our overarching hypothesis. In summary, spatio-temporal selection of reference genes not only lays the foundation for functional genomics research in Glycyrrhiza, but also facilitates these traditional medicinal herbs to reach/maximize their pharmaceutical potential.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hangxia Jin ◽  
Xiaomin Yu ◽  
Qinghua Yang ◽  
Xujun Fu ◽  
Fengjie Yuan

AbstractPhytic acid (PA) is a major antinutrient that cannot be digested by monogastric animals, but it can decrease the bioavailability of micronutrients (e.g., Zn and Fe). Lowering the PA content of crop seeds will lead to enhanced nutritional traits. Low-PA mutant crop lines carrying more than one mutated gene (lpa) have lower PA contents than mutants with a single lpa mutant gene. However, little is known about the link between PA pathway intermediates and downstream regulatory activities following the mutation of these genes in soybean. Consequently, we performed a comparative transcriptome analysis using an advanced generation recombinant inbred line with low PA levels [2mlpa (mips1/ipk1)] and a sibling line with homozygous non-mutant alleles and normal PA contents [2MWT (MIPS1/IPK1)]. An RNA sequencing analysis of five seed developmental stages revealed 7945 differentially expressed genes (DEGs) between the 2mlpa and 2MWT seeds. Moreover, 3316 DEGs were associated with 128 metabolic and signal transduction pathways and 4980 DEGs were annotated with 345 Gene Ontology terms related to biological processes. Genes associated with PA metabolism, photosynthesis, starch and sucrose metabolism, and defense mechanisms were among the DEGs in 2mlpa. Of these genes, 36 contributed to PA metabolism, including 22 genes possibly mediating the low-PA phenotype of 2mlpa. The expression of most of the genes associated with photosynthesis (81 of 117) was down-regulated in 2mlpa at the late seed developmental stage. In contrast, the expression of three genes involved in sucrose metabolism was up-regulated at the late seed developmental stage, which might explain the high sucrose content of 2mlpa soybeans. Furthermore, 604 genes related to defense mechanisms were differentially expressed between 2mlpa and 2MWT. In this study, we detected a low PA content as well as changes to multiple metabolites in the 2mlpa mutant. These results may help elucidate the regulation of metabolic events in 2mlpa. Many genes involved in PA metabolism may contribute to the substantial decrease in the PA content and the moderate accumulation of InsP3–InsP5 in the 2mlpa mutant. The other regulated genes related to photosynthesis, starch and sucrose metabolism, and defense mechanisms may provide additional insights into the nutritional and agronomic performance of 2mlpa seeds.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Sonia Ciccazzo ◽  
Alfonso Esposito ◽  
Eleonora Rolli ◽  
Stefan Zerbe ◽  
Daniele Daffonchio ◽  
...  

The rhizosphere effect on bacterial communities associated with three floristic communities (RW, FI, and M sites) which differed for the developmental stages was studied in a high-altitude alpine ecosystem. RW site was an early developmental stage, FI was an intermediate stage, M was a later more matured stage. The N and C contents in the soils confirmed a different developmental stage with a kind of gradient from the unvegetated bare soil (BS) site through RW, FI up to M site. The floristic communities were composed of 21 pioneer plants belonging to 14 species. Automated ribosomal intergenic spacer analysis showed different bacterial genetic structures per each floristic consortium which differed also from the BS site. When plants of the same species occurred within the same site, almost all their bacterial communities clustered together exhibiting a plant species effect. Unifrac significance value (P<0.05) on 16S rRNA gene diversity revealed significant differences (P<0.05) between BS site and the vegetated sites with a weak similarity to the RW site. The intermediate plant colonization stage FI did not differ significantly from the RW and the M vegetated sites. These results pointed out the effect of different floristic communities rhizospheres on their soil bacterial communities.


1985 ◽  
Vol 5 (1) ◽  
pp. 93-98
Author(s):  
C F Brunk ◽  
R K Conover

After conjugation in Tetrahymena thermophila, the old macronuclei degenerate, and new macronuclei (anlagen) develop. During anlagen development a number of DNA sequences found in the micronuclear genome (micronuclear limited sequences) are eliminated from the anlagen. A cloned copy of a repetitive micronuclear limited sequence has been used to determine the developmental stage at which micronuclear limited sequences are eliminated. DNAs from anlagen of various developmental stages were examined by Southern analysis. It was found that micronuclear limited sequences are present in 4C anlagen and essentially absent in 8C and 16C anlagen. The precipitous loss of these sequences in the 8C anlagen rules out under-replication as the mechanism for the loss and suggests that these sequences are specifically degraded early during anlagen development.


2003 ◽  
Vol 46 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Mozart da Silva Lauxen ◽  
Eliane Kaltchuk- Santos ◽  
Ching -yeh Hu ◽  
Sidia Maria Callegari- Jacques ◽  
Maria Helena Bodanese-Zanettini

This study was carried out to establish the association between floral bud size and the corresponding microspore developmental stages for Brazilian soybean cultivars. Microspore developmental stage distributions were examined in young buds from cv Década, IAS5 and RS7. The data indicated that for a given bud-size group, the microspores of different cultivars were at different developmental stages, with cv RS7 and Década distributed at the youngest and cv IAS5 at the most advanced stages. Microspore stages distribution were also compared among the ten anthers of the same bud of the above cultivars. The ten anthers from a given bud were clearly distributed at different developmental stages. Caution should be exercised when adopting the standard anther culture practice of using the microspore stage of one anther to represent the entire bud.


2017 ◽  
Vol 8 (2) ◽  
pp. 134-140
Author(s):  
Liza Nurul Hayati ◽  
Nurheni Wijayanto ◽  
Yulianti .

Mindi besar (Melia dubia Cavanilles) is one of fast growing tree species from family Meliaceae which growing in tropical evergreen forests. The aim of this study was to determine the best combination of medium and growth regulator for vegetative propagation of mindi besar trees. The completely randomized factorial design was used two factors; medium (M) there were two types of media; zeolite (M1) and soil + rice husk (2:1 v/v) medium (M2), the growth regulator (H) had three levels; control (H0), pure coconut water (H1), and Auksin sintetis (H3). The study was conducted at two locations, first at green house with rooting room KOFFCO System and second at seedbed with rooting room containment model (MS). The research at greenhouse using rooting room KOFFCO System showed that interaction of media with growth regulator had a very significant effect on the percentage of fresh cuttings and rooted cuttings and had a significant effect on the number of primary roots. The averages of percentage of fresh cuttings and rooting were 83.3% and 66.7% for M1H2 and 76% and 60% for M2H0. The M2H1 reached 2.9 number of primary roots. At the MS model, the medium factor had significantly different only the number of secondary roots (18.11). The growth regulator factors had significantly different on the percentage of rooted cutting (3.33%), root lenght (10.5 cm) and root dry weight (0.18 g).Key words: containment model, KOFFCO system, Rootone-F, zeolite.


AGRIFOR ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 153
Author(s):  
Primadiyanti Arsela

The main goal of the study was to determine the effect of various  Papaya varieties and liquid organic fertilizer on the growth of Papaya seedlings(Carica papaya L.). The research used Randomized Block Design (RAK) with two factors factorial experimental. The first factor is Variety (V) consists of 3 Papaya varieties: v1= bangkok , v2= red lady , v3= sunrise. The second factor is Fertilizer (C) consists of 3 brands: c1= Em4 10 ml, c2= Green Tonic 10ml, c3= Nasa 10ml. This study has 3 treatment levels consisting of 9 combinations and  repeated 3 times. The results of the study are treatment of various varieties (V) had significant effect on stem diameter and root number. The effect of various liquid organic fertilizer (C) had significant effect on the root length parameters. The interaction all treatment had a very significant effect on the root length and the root number parameter. 


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