scholarly journals PHYSIOLOGICAL CHANGES ASSOCIATED WITH LEAF SENESCENCE IN EASTER LILIES

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 189a-189
Author(s):  
Rosanne E. Franco ◽  
Susan S. Han

Senescence of lower leaves of Easter lilies (Lilium longiflorum Thunb.) was previously shown to be delayed with application of the growth regulators, gibberellic acid (GA3) and benzyladenine (BA). This study was done to determine the physiological effects of GA3 and BA in relation to the delay of leaf senescence. Foliar application with 500 ppm BA or GA3 delayed chlorosis and lowered respiration rate in Easter lily leaves. A combination of 500 ppm BA and 500 ppm GA3 was more effective than the individual application of each. Gibberellic acid, BA, or their combination before cold storage resulted in delayed chlorosis and lowered respiration following removal from cold storage. Treatment with growth regulators after cold storage was less effective. Senescence of leaves was not associated with ethylene since ethylene production by leaves was undetectable by gas chromatograph. In addition, pulsing or continuous treatment with silver thiosulphate (STS), an inhibitor of ethylene synthesis, did not delay foliar chlorosis. Analysis of carbohydrate levels in Easter lily leaves treated with GA3, BA, or their combination may contribute to the understanding of the physiological effects of these two growth regulators.

2000 ◽  
Vol 125 (2) ◽  
pp. 248-253 ◽  
Author(s):  
Anil P. Ranwala ◽  
William B. Miller ◽  
Terri I. Kirk ◽  
P. Allen Hammer

The interactions of ancymidol drenches, postgreenhouse cold storage, and hormone sprays on postharvest leaf chlorosis and flower longevity of `Nellie White' Easter lilies (Lilium longiflorum Thunb.) were investigated. Ancymidol drenches (0.5 mg/plant twice) during early growth resulted in leaf chlorosis in the greenhouse which intensified further during postharvest. Cold storage (4 °C) of puffy bud stage plants for 2 weeks also accelerated leaf chlorosis. The combination of ancymidol treatment with cold storage resulted in the most severe leaf chlorosis. Promalin (GA4+7 and BA each at 100 mg·L-1) sprays completely prevented postharvest leaf chlorosis, whereas ProGibb (GA3 at 1000 mg·L-1) was ineffective. Cold storage reduced flower longevity and increased bud abortion, however, the degree of bud abortion varied among experiments in different years. Both ProGibb and Promalin sprays increased flower longevity. Compared to positive DIF (difference between day and night temperature) grown plants, forcing under negative DIF (-8 °C) increased the severity of postharvest leaf chlorosis. Leaves were sampled from basal, middle, and upper sections of the stem after 4 and 12 days in a postharvest evaluation room, and analyzed for soluble carbohydrates and N. Total leaf soluble carbohydrates and N concentrations were less in basal and middle sections of negative DIF-grown plants than in positive DIF-grown plants. Leaf chlorosis was associated with depletion of soluble carbohydrates and N in the leaves. Chemical names used: α-cyclopropyl-α-(p-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); gibberellic acid (GA3); gibberellins A4A7 (GA4+7); N-(phenylmethyl)-1H-purine 6-amine (benzyladenine).


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 430g-431
Author(s):  
Susan S. Han

Yellowing of excised Easter lily leaves was significantly delayed by foliar application of gibberellic acids (GA3) ≥ 250 mg·1-1 or benzyladenine (BA) ≥ 50 mg·1-1. Rapid development of foliar chlorosis following cold storage was delayed significantly by applying 500 mg·1-1 of GA3 or BA before storage. Post-storage treatments were less effective. Development of chlorosis was associated with rapid loss of fresh weight and was not related to the aperture of the stomates. Respiration rate of leaves treated with growth regulators were significantly lower than that of the controls. Differences in the rate of carbohydrate depletion may explain the striking effects of growth regulators on the development of foliar chlorosis.


1997 ◽  
Vol 122 (6) ◽  
pp. 869-872 ◽  
Author(s):  
Susan S. Han

Postproduction leaf yellowing of Easter lily (Lilium longiflorum Thunb.) can be prevented by using growth regulators. Solutions containing benzyladenine (BA) reduced the percentage of yellow leaves in cold-stored plants, but solutions containing gibberellic acid (GA3) were not effective. Treatment with commercial products containing GA4+7 (Provide) or GA4+7 and BA (Promalin) nearly completely prevented the development of leaf yellowing. Concentrations as low as 25 mg·L-1 were effective. Leaf yellowing was prevented by growth regulators only on leaves that had been treated, indicating that the growth regulators were not mobilized in the plants. Growth regulator solutions halted further development of leaf yellowing when applied to plants that already had some chlorotic basal leaves. This result suggests that growth regulators need not be applied preventively. Treatment can be delayed until chlorotic lower leaves are first seen on plants. The striking effects of growth regulators in preventing leaf yellowing did not affect the development and opening of flower buds.


1997 ◽  
Vol 122 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Rosanne E. Franco ◽  
Susan S. Han

Senescence of excised Easter lily leaves is typically marked by a rise in respiration without a concomitant production of ethylene. Treating excised leaves with 500 mg·L-1 of gibberellic acid (GA3) or benzyladenine (BA) significantly delayed the onset of leaf yellowing, lowered the respiration rates by one-third to one-half, and markedly delayed the respiratory rise. Similar effects on respiration were detected in leaves treated with BA or GA3 before a 4-week period of cold storage and in leaves treated after chlorosis had initiated. Results of this study indicate that excised Easter lily leaves respond to the growth regulators with a significant decrease in respiration rate.


1978 ◽  
Vol 58 (1) ◽  
pp. 287-290 ◽  
Author(s):  
M. J. TSUJITA ◽  
D. P. MURR ◽  
A. G. JOHNSON

Severity of lower foliage senescence of Easter lilies (Lilium longiflorum Thunb.) was increased in response to application of ancymidol (A-Rest) in combination with low phosphorus nutrition. Leaf senescence in lilies could be related to a reduced foliar content of phosphorus and total chlorophyll. Plant growth was significantly retarded by high rates of A-Rest. Maintaining high phosphorus nutrition lessened the severity of leaf senescence but partially overcame the effect of A-Rest on growth.


2016 ◽  
Vol 47 (2) ◽  
Author(s):  
N. H. Khalil

An experiment was conducted in unheated greenhouse units of the Department of Horticulture and Landscape -College of Agriculture- University of Baghdad on the first of October,   to observe the effects of amony interaction of crown diameter, chilling,  and foliar application of gibberellic acid on vegetative growth, and reproductive in cv. ‘Festival’ of strawberry (Fragaria x ananassa (Duch)). Using randomized Complete Block Design (RCBD), Plants were sorted into two groups according to crown diameter (11-15mm (Cd1)  and  6-10 mm (Cd2)), each of them sorted into two groups [Ch0 (without cold storage) and Ch1 (kept in a cold storage for  three weeks at 1-2°C), gibberellic acid was sprayed on plants, with concentration treatments included a control (G0) (distilled water), 150 mg. L–1 (G1) and 300 mg. L–1 (G2).The results showed the highest leaf number and Leaf area. Plant-1, (26.33), (29.70 dcm2) in (Cd1.Ch1.GA0) and (Cd1.Ch1. GA1) respectively, Number of stolon increased significantly by GAs application, the highest number were (8.3) in (Cd1.Ch1. GA2). The highest value of the TSS % was produced from the plants under the effect of  the treatment (Cd1.Ch1. GA0) (8.5%) and the highest pH were 3.70 from the treatment (Cd2.Ch0.GA2). The results indicated the superiority of treatment (Cd1.Ch0.GA0)     in fruit number (22.4), weight (17.77g) and a plant yield (398.2g).


HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 657-660 ◽  
Author(s):  
Susan S. Han

The development of greenhouse leaf yellowing in Easter lilies (Lilium longiflorum Thunb.) was significantly reduced by the application of growth regulator solutions containing gibberellins 4 and 7 (GA4+7) or benzyladenine (BA). Solutions containing BA alone significantly reduced leaf yellowing on plants caused by close spacing but were less effective than GA4+7. Application of BA alone, however, was not effective against root rot-induced leaf yellowing. When plants were treated with GA4+7 or BA + GA4+7 around the visible bud stage, nearly all of the leaves remained green until the end of the growing season. These growth regulators, however, increased the final height of the plants by 8–10 cm. The developmental rate and size of the flower buds, as well as the length of the pedicels were not affected by the growth regulator treatments. Thus application of these growth regulators greatly improved the quality of the leaves without compromising the quality and timing of the flowers. Chemical name used: N-(phenylmethyl)-1H-purine-6-amine (benzyladenine, BA).


2005 ◽  
Vol 50 (1) ◽  
pp. 27-32
Author(s):  
Slavica Todic ◽  
Z. Beslic

The effect of foliar application of plant growth regulators, paclobutrazol (1000 mg/L), chlorcholine chloride (200 mg/L) and gibberellic acid (100 mg/L) on leaf water status in grapevine graftlings of cv Cardinal was investigated. After stratification and waxing, young vines were planted into vegetation pots and grown in a glasshouse. Foliar treatments were applied once, twice or three times during the vegetative period, starting on 25 July and every 15 days thereafter. Values of total water potential (Tl) and of relative water content (RWC) were measured over the same period. Results indicate a tendency of increased TL values in leaves of plants repeatedly treated with a growth inhibitor paclobutrazol (-1.18 Mpa) compared with untreated (-1.36 Mpa) as well as plants treated twice with gibberellic acid (-1.37 Mpa). RWC in leaves was significantly increased in the second half of the vegetative period when paclobutrazol was applied twice (78%) in comparison with control (75%). Values of both investigated indices point to a more favorable water status of plants treated during the vegetative period with growth inhibitors compared with untreated and plants treated with gibberellic acid.


1984 ◽  
Vol 102 (2) ◽  
pp. 437-442 ◽  
Author(s):  
Lynda D. Wickham ◽  
H. C. Passam ◽  
L. A. Wilson

SummaryWhen pre-harvest foliar applications of growth regulators were made to vines of Dioscorea esculenta cv. Chinese Yam and D. alata cv. White Lisbon there were no obvious effects on tubers of D. alata, but dramatic effects on tuber development, storage and germination were obtained with D. esculenta tubers. Gibberellic acid caused marked extensions in tuber dormancy, 2,4-dichlorophenoxyacetic acid resulted in marked callus development, delayed germination and abnormal shoot and root development and indole acetic acid resulted in fingering of the tubers. It was concluded that there was potential for commercial exploitation of pre-harvest gibberellic acid treatments in extension of dormancy in Chinese Yam tubers and that the lack of response of D. alata tubers to foliar application of growth regulators warranted further investigation.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 459B-459
Author(s):  
Susan S. Han

The marked effects of growth regulators such as GA3 and BA in delaying leaf yellowing on excised leaves of Easter lilies decreased when studies were conducted on intact plants in a simulated interior environment. Solutions containing benzyladenine (BA) delayed the development of leaf yellowing in cold-stored plants, but solutions containing gibberellic acid (GA3) were not effective when applied to plants at the puffy bud stage and evaluated in a 22.6 ± 0.2°C room illuminated 12 h/day with 11.2 ± 0.1 μmol·s–1·m–2 cool-white fluorescent lamp. Treatment with commercial products containing GA4+7 (Provide) or GA4+7 and BA (Promalin) nearly completely prevent the development of leaf yellowing. Concentrations as low as 25 mg·L–1 were effective. The prevention of leaf yellowing by growth regulators was only effective on leaves that had been treated, indicating that mobilization of the growth regulators in the plants did not occur. Growth regulator solutions halted further development of leaf yellowing when applied to plants that already possessed some chlorotic, basal leaves. The striking effects of growth regulators on preventing leaf yellowing did not affect the development and opening of the flower buds and is a practical solution for the prevention of post-production leaf yellowing in Easter lilies.


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