RESPONSES OF CUCUMBER, ONION AND POTATO CULTIVARS TO OZONE

1971 ◽  
Vol 51 (4) ◽  
pp. 283-288 ◽  
Author(s):  
D. P. ORMROD ◽  
N. O. ADEDIPE ◽  
G. HOFSTRA

Cucumber, onion and potato plants were grown in the greenhouse. At 2 to 3 weeks from seeding they were fumigated with ozone for short periods. Observations on the development of leaf injury symptoms and of growth effects were made over a 4-week post-fumigation period. Generally, when the plants were fumigated with 100 pphm ozone for 1 hour, there were no marked responses. Fumigation at the same concentration for 4 hours resulted in a reduction in dry weight, accompanied by leaf injury symptoms. The magnitude of such effects varied with species and cultivars. Percent reduction in dry weight ranged up to 37 in cucumber, and 47 in onion. Inhibition of flowering of potato plants was accompanied by accelerated leaf senescence. Susceptibility of the species to ozone, in decreasing order, followed the sequence: onion, cucumber, potato. In each case there was at least one relatively tolerant cultivar.

1996 ◽  
Vol 26 (4) ◽  
pp. 649-657 ◽  
Author(s):  
M.S. Günthardt-Goerg ◽  
P. Schmutz ◽  
R. Matyssek ◽  
J.B. Bucher

Although increasing tropospheric ozone (O3) concentrations as well as precursor NO2 emissions and N deposition have been observed, the combination of their effects on deciduous trees is little understood. We therefore examined the growth and leaf injury response of a model tree (Populus ×euramericana (Dode) Guinier cuttings exposed before flush and until they reached a height of more than 1 m) to low and high soil N supply (105 or 315 mg N•L−1 substrate volume), to filtered air, and to filtered air with NO2 (sinusoidal daily course with a mean of 100 nL•L−1), with O3 (60 nL•L−1), or with a combination of both in climate-controlled chambers. High soil N increased total plant dry weight, leaf area, and xylem radius in plants fumigated with or without added NO2 or O3. The number of leaves increased with high soil N independent of added NO2. The stomatal density was influenced by soil N and by fumigations, but the appearance of leaf injury symptoms, leaf loss, specific leaf weight, and bark radius were not modified by the soil N regimes. NO2 alone, though applied in a sixfold ambient concentration, did not significantly increase plant growth. NO2 and O3 alone had opposite effects on specific leaf dry weight, stomatal density, and in the high fertilization regime, on the bark radius. The decrease in specific leaf dry weight and the appearance of early leaf symptoms were enhanced by NO2 added to O3. Visible leaf injury caused by O3 increased in parallel with microscopic changes in mesophyll cell walls, in the starch and protein patterns of mesophyll cells, in the bark cell content, and in the phloem sieve pores. NO2 enhanced the negative effect of O3 rather than compensated for a low soil N supply.


2007 ◽  
pp. 165-169
Author(s):  
M.B. Khorshidi ◽  
F. Rahimsade Khoii ◽  
M.J. Mir Hadi ◽  
G. Noor Mohamadi

1980 ◽  
Vol 10 (1) ◽  
pp. 78-81 ◽  
Author(s):  
W. Suwannapinunt ◽  
T. T. Kozlowski

Effects of SO2 on transpiration, chlorophyll content, growth, and injury of woody angiosperm seedlings were studied during the first few weeks after germination. Fumigation of silver maple (Acersaccharinum L.) and black locust (Robiniapseudoacacia L.) seedlings with SO2 at 0.75 ppm for 2 to 16 h increased transpirational water loss. As duration of fumigation was increased, the effect of SO2 on increasing transpiration declined. Leaves of silver maple seedlings fumigated with SO2 at 0.75 ppm for 8 to 16 h were injured; those of black locust were not. In another experiment, the adverse effects of SO2 were greater on black locust than on American elm (Ulmusamericana L.) seedlings. Fumigation of young black locust seedlings with SO2 at 2 ppm for 1 or 4 h significantly reduced chlorophyll content, height growth, dry weight increment of roots, and leaf formation. Leaf injury symptoms appeared within 24 h after fumigation with 2 ppm SO2 for 4 h. Fumigation of American elm seedlings with SO2 at 0.5 or 2 ppm for 0.5 to 4 h decreased dry weight increment of roots but did not injure plants or significantly influence chlorophyll content, height growth, or leaf dry weight. Inhibition of dry weight increment of roots was a more sensitive indicator of susceptibility to SO2 than was reduction in dry weight increment of shoots.


HortScience ◽  
2016 ◽  
Vol 51 (12) ◽  
pp. 1452-1457 ◽  
Author(s):  
Ryan W. Dickson ◽  
Paul R. Fisher ◽  
Sonali R. Padhye ◽  
William R. Argo

Floriculture crop species that are inefficient at iron uptake are susceptible to developing iron deficiency symptoms in container production at high substrate pH. The objective of this study was to compare genotypes of iron-inefficient calibrachoa (Calibrachoa ×hybrid Cerv.) in terms of their susceptibility to showing iron deficiency symptoms when grown at high vs. low substrate pH. In a greenhouse factorial experiment, 24 genotypes of calibrachoa were grown in peat:perlite substrate at low pH (5.4) and high pH (7.1). Shoot dry weight, leaf SPAD chlorophyll index, flower index value, and shoot iron concentration were measured after 13 weeks at each substrate pH level. Of the 24 genotypes, analysis of variance (ANOVA) found that 19 genotypes had lower SPAD and 18 genotypes had reduced shoot dry weight at high substrate pH compared with SPAD and dry weight at low substrate pH. High substrate pH had less effect on flower index and shoot iron concentration than the pH effect on SPAD or shoot dry weight. No visual symptoms of iron deficiency were observed at low substrate pH. Genotypes were separated into three groups using k-means cluster analysis, based on the four measured variables (SPAD, dry weight, flower index, and iron concentration in shoot tissue). These four variables were each expressed as the percent reduction in measured responses at high vs. low substrate pH. Greater percent reduction values indicated increased sensitivity of genotypes to high substrate pH. The three clusters, which about represented high, medium, or low sensitivity to high substrate pH, averaged 59.7%, 42.8%, and 25.2% reduction in SPAD, 47.7%, 51.0%, and 39.5% reduction in shoot dry weight, and 32.2%, 9.2%, and 27.7% reduction in shoot iron, respectively. Flowering was not different between clusters when tested with ANOVA. The least pH-sensitive cluster included all four genotypes in the breeding series ‘Calipetite’. ‘Calipetite’ also had low shoot dry weight at low substrate pH, indicating low overall vigor. There were no differences between clusters in terms of their effect on substrate pH, which is one potential plant iron-efficiency mechanism in response to low iron availability. This experiment demonstrated an experimental and statistical approach for plant breeders to test sensitivity to substrate pH for iron-inefficient floriculture species.


Plant Disease ◽  
2018 ◽  
Vol 102 (1) ◽  
pp. 185-196 ◽  
Author(s):  
Roger A. C. Jones ◽  
Stuart J. Vincent

Strain-specific hypersensitive (HR) and extreme resistance (ER) phenotypes elicited in potato plants by three Potato virus Y (PVY) isolates in strain groups PVYO (BL and DEL3) and PVYD (KIP1) were studied. PVYO and PVYD isolates elicit HR genes Ny or putative Nd, respectively, and all three isolates elicit ER gene Ry. They were inoculated to 39 Australasian, European, or North American potato cultivars released over a 117-year period and harvested tubers were replanted. Both primary and secondary symptoms were recorded. Two European cultivars always developed ER following sap and graft inoculation and, thus, carried comprehensive PVY resistance gene Ry. One Australasian and two European cultivars always developed susceptible phenotypes and, thus, lacked genes Ry, Ny, and putative Nd. Sap inoculation with isolate KIP1 elicited localized HR (LHR) in 31 cultivars and both LHR and systemic HR (SHR) in three others; thus, all carried putative Nd. Isolates BL and DEL3 both elicited susceptible phenotypes in 11 of these 34 cultivars but LHR alone, SHR alone, or both LHR and SHR in the other 23 which, therefore, all carry Ny. With these two isolates, SHR expression ranged from very severe to very weak, with the greatest numbers of isolate–cultivar combinations occurring in the severe category with BL (n = 11) and moderate category (n = 12) with DEL3. Within the same isolate–cultivar combination, overall, SHR symptom expression was weaker with secondary than primary infection. With both primary and secondary infection, SHR expression was most severe with KIP1 and weakest with DEL3. Genes Ny and putative Nd were present in cultivars released between 1939 and 2010 or 1893 and 2010, respectively, occurring in cultivars from all three world regions. These findings have important implications concerning breeding new PVY-resistant potato cultivars, especially for countries lacking healthy seed potato stocks, or where subsistence farmers cannot afford them. An alternative to including gene Ry is incorporating as many strain-specific PVY resistance genes as possible.


HortScience ◽  
2013 ◽  
Vol 48 (6) ◽  
pp. 756-761 ◽  
Author(s):  
Genhua Niu ◽  
Terri Starman ◽  
David Byrne

The responses of garden roses to irrigation water with elevated salts are unknown. Two experiments were conducted to evaluate the relative salt tolerance of 13 self-rooted rose cultivars by irrigating the plants with nutrient solutions at an electrical conductivity (EC) of 1.4 dS·m−1 (control) or nutrient saline solutions at EC of 3.1, 4.4, or 6.4 dS·m−1. In Expt. 1, ‘Belinda’s Dream’, ‘Caldwell Pink’, ‘Carefree Beauty’, ‘Folksinger’, ‘Quietness’, and ‘Winter Sunset’ plants were grown in a greenhouse from 13 Aug. to 21 Oct. (10 weeks). Shoot dry weight of all cultivars decreased as EC of irrigation water increased. ‘Winter Sunset’ was most sensitive among these cultivars to salt stress followed by ‘Carefree Beauty’ and ‘Folksinger’ with severe leaf injury at EC of 3.1 dS·m−1 or higher or death at EC of 6.4 dS·m−1. No visual damage was observed in ‘Belinda’s Dream’ or ‘Caldwell Pink’, regardless of the salinity level. In Expt. 2, ‘Basye’s Blueberry’, ‘Iceberg’, ‘Little Buckaroo’, ‘The Fairy’, ‘Marie Pavie’, ‘Rise N Shine’, and ‘Sea Foam’ plants were grown in the greenhouse from 29 Sept. to 16 Nov. (7 weeks) and irrigated with the same nutrient or nutrient saline solutions. Salinity treatment did not affect shoot dry weight of ‘Basye’s Blueberry’, ‘Little Buckaroo’, ‘Sea Foam’, and ‘Rise N Shine’. Shoot dry weight of ‘Iceberg’, ‘The Fairy’, and ‘Marie Pavie’ decreased as EC of irrigation water increased. No or little visual damage was observed in ‘Little Buckaroo’, ‘Sea Foam’, and ‘Rise N Shine’. Leaf tip burns were seen in ‘Iceberg’, ‘Marie Pavie’, ‘Basye’s Blueberry’, and ‘The Fairy’ at EC 6.4 of dS·m−1. Generally, these symptoms were less severe than those observed in Expt. 1, probably attributable partially to the shorter treatment period. Whereas shoot Na+ and Cl– varied greatly among the rose cultivars, the shoot concentrations of Ca2+, K+, and Mg2+ did not. Generally, salinity-tolerant cultivars had higher shoot Na+ and Cl– concentrations. In summary, in Expt. 1, ‘Belinda’s Dream’ was the most tolerant cultivar, whereas ‘Winter Sunset’ was the least tolerant followed by ‘Carefree Beauty’. In Expt. 2, ‘Iceberg’, ‘Marie Pavie’, and ‘The Fairy’ were less tolerant to salinity as compared with other cultivars, although the differences were small.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1166d-1166 ◽  
Author(s):  
J. Scott Cameron ◽  
Carol A. Hartley ◽  
Carl H. Shanks ◽  
Jeannie K. L. Garth

At two-week intervals from 17 June to 15 July, three groups of `Meeker' red raspberry plants were infested with two-spotted spider mites (Tetranychus urticae) in a greenhouse. While populations on individual plants were allowed to develop freely, control plants were kept free of mites with a chemical miticide. Gas exchange measurements were made on 27 July prior to visible mite damage, and on 7 October after injury was apparent. The relationships between mite populations and leaf gas exchange and chlorophyll characteristics were described using a logarithmic function.Physiological responses to mite feeding were observed prior to visible leaf injury. On both dates, CO2 assimilation rates decreased (p ≤ 0.001) with increasing mite numbers per leaflet. On 27 June, a significant relationship (R2 = 0.61***) was found between mite number and mesophyll conductance (gm). On 7 October, significant relationships (p ≤ 0.001) were also observed with gm, stomatal conductance (gs), and transpiration (E). Total chlorophyll content of leaves decreased with increasing mite populations, but chlorophyll a/b ratio and dry weight per leaf unit area were unchanged.


HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 771-774 ◽  
Author(s):  
Youbin Zheng ◽  
Linping Wang ◽  
Diane Feliciano Cayanan ◽  
Mike Dixon

To determine the nutrient solution copper (Cu2+) level above which Cucumis sativus L. (cucumber, cv. LOGICA F1) plant growth and fruit yield will be negatively affected, plants were grown on rockwool and irrigated with nutrient solutions containing Cu2+ at 0.05, 0.55, 1.05, 1.55, and 2.05 mg·L−1. Copper treatment began when plants were 4 weeks old and lasted for 10 weeks. During this 10-week period, plants were harvested at 3 weeks (short-term) and 10 weeks (long-term) after the start of Cu2+ treatment. Neither visible leaf injury nor negative Cu2+ effect was observed on plant growth (leaf number, leaf area, leaf dry weight, and stem dry weight) after 3 weeks of continuous Cu2+ treatment. However, after 10 weeks of continuous Cu2+ application, cucumber leaf dry weight was significantly reduced by Cu2+ levels 1.05 mg·L−1 or greater; leaf number, leaf area, and stem dry weight were significantly reduced by Cu2+ levels 1.55 mg·L−1 or greater. Copper (Cu2+ levels 1.05 mg·L−1 or greater) also caused root browning. Some plants under the 2.05 mg·L−1 Cu2+ treatment started to wilt after 6 weeks of continuous Cu2+ treatment. Copper treatment did not result in any change in leaf greenness until after Week 9 from the start of the treatments. There was no sign of a negative Cu2+ effect on cucumber fruit numbers after the first 2 weeks of production, but plants under the highest Cu2+ concentration treatment (2.05 mg·L−1) gradually produced fewer cucumber fruit than the control (0.05 mg·L−1) and eventually resulted in lower cucumber yield. Nutrient solution can be treated with 1.05 mg·L−1 of Cu2+ in cucumber production greenhouses; however, it is not recommended to use Cu2+ concentrations 1.05 mg·L−1 or greater continuously long-term (more than 3 weeks). When applying Cu2+, it is suggested that cucumber roots be examined regularly because roots are a better indicator for Cu2+ toxicity than leaf injury.


2016 ◽  
Vol 4 (2) ◽  
pp. 207-212
Author(s):  
M.K. Hasan ◽  
K.M. Nasiruddin ◽  
M. Al-Amin ◽  
A.K.M.S. Hossain

Salinity is one of the most limiting factors for successful crop production in in arid and semi-arid regions of the world. Thirty eight soybean genotypes were screened at 8mMNaCl under in vitro condition. Salinity reduced Shoot dry weight, Root dry weight and Plant height. Salt susceptibility index was fully and positive correlated with percent reduction of total dry weight. Principal component analysis showed that the first two components were extracted that comprises of about 98.6% of the total variation in the genotypes. Based on the K-means clustering, 8, 6, 12 and 12 genotypes were categorized under cluster II, IV, III and I and considered as tolerant, moderately tolerant, moderately susceptible and susceptible which represents the 21, 16, 31.5 and 31.5%, respectively. Genotypes Shohag, AGS 313, PK 416, AGS 66, MACS 57, AGS 195, GC 308, AGS 129 were found relatively tolerant to salinity.Int J Appl Sci Biotechnol, Vol 4(2): 207-212


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