scholarly journals Florigenic Effect of Gibberellin on Flowering According to Period of Chilling Treatment in Lavandula × intermedia

2016 ◽  
Vol 85 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Masaji Koshioka ◽  
Taiga Horimoto ◽  
Yoshiyuki Muramatsu ◽  
Satoshi Kubota ◽  
Tamotsu Hisamatsu
Keyword(s):  
1997 ◽  
Vol 77 (1) ◽  
pp. 97-99 ◽  
Author(s):  
L. V. Gusta ◽  
B. J. O'Connor ◽  
R. S. Bhatty

The effect of a 5 °C chilling treatment at the seedling stage on days to flower, yield and oil quality and quantity was determined for seven cultivars of flax (Linum usitatissimum L.). Three days of chilling delayed flowering in Dufferin, McGregor and NorLin, whereas 5 d of chilling delayed flowering in all cultivars except Andro and Noralta. Seven days of chilling reduced the seed yield of only McGregor, Norlin, NorMan and Vimy. The effect of a 40 °C heat stress at the flowering stage on yield and oil composition was determined for the same seven cultivars. A heat stress of 40 °C for 3 d reduced the seed yield of NorMan, whereas, a 5 d stress reduced the seed yield of all cultivars except McGregor and Noralta. The composition of the oil was not affected by the heat stress. These results suggest genetic variability exists among flax cultivars for tolerance to chilling and heat stresses. Controlled tests can be used to select superior stress tolerant genotypes. Key words: Flax, chilling, heat, flowering, yield


1992 ◽  
Vol 61 (2) ◽  
pp. 287-293 ◽  
Author(s):  
Yoshikazau Nakajima ◽  
Slamet Susanto ◽  
Kojiro Hasegawa

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 618d-618
Author(s):  
Chin-Chang Chu ◽  
Kenneth W. Mudge

Seeds from mature seed pods of Cypripedium calceolus var. parviflorum were germinated on 1/4 MSMO (Sigma) + 100ml/l coconut water + 1% sucrose +/- 8g/l agar (pH 6.0), and with or without prechilling at 5C for 8 weeks. Protocorm with apex (stage 3) was use as an index of germination. Seeds sown on agar medium withou chilling treatment resulted in a 40% germination rate in 120 days but the germination was very uneven. Seeds germinated on agar medium with prechilling developed more synchronously with 92% germination in 60 days (ie. about 120 days after sowing). Suspension culture of seeds without prechilling resulted in 85% germination after 90 days. The synchronization of seed germination in suspension culture was intermediate between that on agar with and without prechilling. Protocorms germinated in suspension culture appeared morphologically identical to those germinated on agar medium. All stage 3 protocorms developed further on the same agar medium in darkness. Both agar and suspension culture in media containing coconut water provided reliable seed germination methods for this orchid species.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 537C-537
Author(s):  
J.G. Williamson ◽  
R.L. Darnell

Two-year-old, container-grown `Misty' southern highbush blueberry plants were sprayed to drip with two concentrations of hydrogen cyanamide (HCN) (20.4 g·L–1 and 10.2 g·L–1) after exposure to 0, 150, or 300 hr of continuous chilling at 5.6°C. All plants were sprayed immediately after chilling and placed in a greenhouse for several weeks. The plants were moved outdoors during flowering to increase cross-pollination from nearby `Sharpblue' blueberry plants. HCN sprays killed some of the more advanced flower buds on shoot terminals and on small-diameter wood from the previous spring growth flush. Significantly greater flower bud mortality occurred for the 20.4 g·L–1 HCN sprays than for the 10.2 g·L–1 sprays. Flower buds subjected to 0 hr of chilling were more susceptible to spray burn than flower buds receiving 150 or 300 hr of chilling. Very little flower bud death occurred with the 10.2 g·L–1 HCN rate on plants receiving 300 hr of chilling. Vegetative budbreak was advanced for both HCN treatments compared to controls, regardless of chilling treatment. HCN-treated plants were heavily foliated at full bloom, while non-treated plants had very few to no leaves during bloom. HCN may be useful for stimulating vegetative growth in some southern highbush blueberry cultivars that suffer from poor foliation during flowering and fruit set.


2010 ◽  
Vol 1 (2) ◽  
pp. 17
Author(s):  
Shashi Sharma ◽  
Rajender Kumar Sharma

Henbane (Hyoscyamus niger L.), an economically important medicinal plant, has an endangered status in Himachal Pradesh (India) that needs appropriate conservation interventions. We have examined seed physiological aspects of H. niger from Lahaul (Himachal Pradesh, India), a cold desert region. The freshly harvested seeds exhibited complete dormancy. Gibberellic acid (GA3) and chilling treatment strongly promoted seed germination which was accompanied by increased α-amylase activity. KNO3, NaN3 and sodium nitroprusside (SNP), an NO donor, also promoted germination. During storage, the seeds retained high viability even after a storage of 72 months under ambient conditions. However, they remained dormant during the entire storage period. The responsiveness of seeds to GA3 and chilling treatment gradually declined with progression of storage period. Concomitantly, the triphenyl tetrazolium chloride (TTC) reduction ability of seeds was lowered. The seed responsiveness to KNO3, NaN3 and SNP during storage increased until one year and decreased thereafter. With the progression of the storage period, seeds exhibited elevated lipid peroxidation and reduced catalase activity implying a role of oxidative stress in observed changes. The involvement of phenolics in seed dormancy of H. niger was not evident. The findings are of significance for conservation and cultivation of H. niger through seeds in the arid mountain region.


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