Effect of Mycorrhizal Fungi on Gas Exchange of Micropropagated Guava Plantlets (Psidium guajava L.) during Acclimatization and Plant Establishment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501c-501
Author(s):  
Andrés A. Estrada-Luna ◽  
Jonathan N. Egilla ◽  
Fred T. Davies

The effect of mycorrhizal fungi on gas exchange of micropropagated guava plantlets (Psidium guajava L.) during acclimatization and plant establishment was determined. Guava plantlets (Psidium guajava L. cv. `Media China') were asexually propagated through tissue culture and acclimatized in a glasshouse for eighteen weeks. Half of the plantlets were inoculated with ZAC-19, which is a mixed isolate containing Glomus etunicatum and an unknown Glomus spp. Plantlets were fertilized with modified Long Ashton nutrient solution containing 11 (g P/ml. Gas exchange measurements included photosynthetic rate (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and vapor pressure deficit (VPD). Measurements were taken at 2, 4, 8 and 18 weeks after inoculation using a LI-6200 portable photosynthesis system (LI-COR Inc. Lincoln, Neb., USA). Two weeks after inoculation, noninoculated plantlets had greater A compared to mycorrhizal plantlets. However, 4 and 8 weeks after inoculation, mycorrhizal plantlets had greater A, gs, Ci and WUE. At the end of the experiment gas exchange was comparable between noninoculated and mycorrhizal plantlets.

2014 ◽  
Vol 522-524 ◽  
pp. 1055-1058
Author(s):  
Jing Li ◽  
Xiao Guang Wang ◽  
Gui Zhai Zhang ◽  
Xue Wei Hou ◽  
Xiao Ming Li

Response of gas exchange to VPD in leaves of four trees (Prunus serrulata, Prunus lannesiana, Populus deltoides I-69 (I-69) and Populus × euramericana Neva (I-107)) at the campus of Shandong University in Jinan, Shandong Province were measured. The result showed that: the stomatal conductance increased with increasing VPD, and gs reached gs-max at intermediate VPD, and a steady decline in gs with further increases in VPD. This response pattern was fitted by a parabolic curve (gs=aD2+bD+c, D=VPD, R2>0.52). The gs-max at intermediate VPD with changing VPD showed that there was an optimal VPD (or RH) to plants. Therefore, while VPD (or RH) was higher or lower than the optimal VPD (or RH) of plant, gs would decrease. The response of gs to VPD in I-69 and I-107 were much more sensitive than P. serrulata and P. lannesiana.


2019 ◽  
Author(s):  
Weichang Gong ◽  
Yaqing Chen ◽  
Jian Wang ◽  
Han Yuan

Abstract Background Inter-specific hybridizations were common and can easily take place in Buddleja , and it was an important way for evolution and rapid speciation. The F1 hybrid in this study was a newly identified inter-specific hybridization between B. crispa and B. offic inalis in Sino-Himalayan region. In the natural hybrid zones, F1 hybrids always occupy different habitats from their parents. The objective of this study was to explore environmental acclimatization of F1 hybrids and their parents at physiological and biochemical levels.Results The results showed that F1 hybrids performed as an intermediate in adaptation to their parents, with divergent gas-exchange and chlorophyll fluorescence features. F1 hybrids showed the parallel light compensation point and light saturation point with their parents, but low utilization efficiency to low-light density. They synthesized the greatest total chlorophyll content (10.41 ± 0.56 mg•g -1 ) in leaves than their parents. During the diurnal variation of photosynthesis, F1 hybrids markedly decreased and preserved the stomatal conductance and leaf transpiration rate at a low level. However, they kept high carbon assimilation rate and water-use efficiency with markedly increased vapor pressure deficit. In F1 hybrids, the maximum net photosynthetic rate, maximum water-use efficiency and maximum vapor pressure deficit were 10.48 ± 0.50 mmol CO 2 •mmol -1 photo, 21.52 ± 2.20 µmol•mmol -1 and 4.18 ± 0.55 kPa, respectively. In addition, all Buddleja species performed well and grow healthy with high level of the maximum photochemical efficiency of PSII and low non-photochemical quenching, 0.83 ± 0.004 - 0.85 ± 0.004, and 1.22 ± 0.15 - 1.97 ± 0.08, respectively. In F1 hybrids, they showed great photochemical activity compared to their parental species with high photochemical quenching. Furthermore, the effective quantum yield and electron transport rate presented a similar behavior.Conclusions The results indicated that F1 hybrids have great photochemical activities and growth acclimatization compared to their parents. Associated with the growth performance of F1 hybrids in the homogenous garden, our results suggested that the divergent gas-exchange and chlorophyll fluorescence patterns may facilitate F1 hybrids to respond to different habitats, and to improve growth performance.


2016 ◽  
Vol 44 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Bianca do Carmo SILVA ◽  
Pêola Reis de SOUZA ◽  
Daihany Moraes CALLEGARI ◽  
Vanessa Ferreira ALVES ◽  
Allan Klynger da Silva LOBATO ◽  
...  

Boron (B) is a very important nutrient required by forest plants; when supplied in adequate amounts, plants can ameliorate the negative effects of abiotic stresses. The objective of this study was to (i) investigate gas exchange, (ii) measure oxidant and antioxidant compounds, and (iii) respond how B supply acts on tolerance mechanism to water deficit in young Schizolobium parahyba plants. The experiment employed a factorial that was entirely randomised, with two boron levels (25 and 250 µmol L-1, simulating conditions of sufficient B and high B, respectively) and two water conditions (control and water deficit). Water deficit induced negative modifications on net photosynthetic rate, stomatal conductance and water use efficiency, while B high promoted intensification of the effects on stomatal conductance and water use efficiency. Hydrogen peroxide and electrolyte leakage of both tissues suffered non-significant increases after B high and when applied water deficit. Ascorbate levels presented increases after water deficit and B high to leaf and root. Our results suggested that the tolerance mechanism to water deficit in young Schizolobium parahyba plants is coupled to increases in total glutathione and ascorbate aiming to control the overproduction of hydrogen peroxide and alleviates the negative consequences on electrolyte leakage and gas exchange. In relation to B supply, this study proved that sufficient level promoted better responses under control and water deficit conditions.


Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 135 ◽  
Author(s):  
Carolin Weiler ◽  
Nikolaus Merkt ◽  
Jens Hartung ◽  
Simone Graeff-Hönninger

Climate change will lead to higher frequencies and durations of water limitations during the growing season, which may affect table grape yield. The aim of this experiment was to determine the variability among 3-year old table grape cultivars under the influence of prolonged water deficit during fruit development on gas exchange, growth, and water use efficiency. Six own rooted, potted table grape cultivars (cv. ‘Muscat Bleu’, ‘Fanny’, ‘Nero’, ‘Palatina’, ‘Crimson Seedless’ and ‘Thompson Seedless’) were subjected to three water deficit treatments (Control treatment with daily irrigation to 75% of available water capacity (AWC), moderate (50% AWC), and severe water deficit treatment (25% AWC)) for three consecutive years during vegetative growth/fruit development. Water deficit reduced assimilation, stomatal conductance, and transpiration, and increased water use efficiencies (WUE) with severity of water limitation. While leaf area and number of leaves were not affected by treatments in any of the tested cultivars, the response of specific leaf area to water deficit depended on the cultivar. Plant dry mass decreased with increasing water limitation. Overall, high variability of cultivars to gas exchange and water use efficiencies in response to water limitation was observed. ’Palatina’ was the cultivar having a high productivity (high net assimilation) and low water use (low stomatal conductance) and the cultivar ‘Fanny’ was characterized by the highest amount of total annual dry mass as well as the highest total dry mass production per water supplied during the experiment (WUEDM). Hence, ‘Fanny’ and ‘Palatina’ have shown to be cultivars able to cope with water limiting conditions and should be extensively tested in further studies.


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