Changes in Carbohydrate Metabolism in ‘Housui’ Japanese Pear Floral Buds Exposed to Different Temperatures During Endodormancy Under Mild Winter Conditions

To investigate the effects of environmental factors on tulip (Tulipa sp.) cultivars in the plains of West Bengal, a field experiment was conducted with ten tulip cultivars, considered as ten treatments (T) (T1=Apeldorn, T2=Maureen, T3=Holland Cich, T4=Day Dream, T5=Pussima Design, T6=Avignon, T7=Roi-du-midi, T8=Clear Water, T9=Colouch and T10=Jumbo Beauty), at Horticultural Research Station, Bidhan Chandra Krishi Viswavidyalaya, Mondouri, Nadia, West Bengal, India in two successive years of 2013-14 and 2014-15. Flower yield, flower length (cm), flower diameter (cm), plant height (cm) etc were observed and statistically analyzed and correlation was done between the morphological data and the environmental factors. The results showed that the short duration cultivars could be more suitable for cultivation under the short and mild winter conditions of the plains of West Bengal.

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Budbreak Number in Apple Seedlings as Selection Criterion for Improved Adaptability to Mild Winter Climates

HortScience ◽

10.21273/hortsci.38.6.1186 ◽

2003 ◽

Vol 38 (6) ◽

pp. 1186-1190 ◽

Cited By ~ 4

Author(s):

Iwan F. Labuschagné ◽

J.H. Louw ◽

Karin Schmidt ◽

Annalene Sadie

Keyword(s):

Environmental Conditions ◽

Selection Criterion ◽

Shoot Length ◽

Natural Conditions ◽

Mild Winter ◽

Winter Conditions ◽

Important Symptom ◽

Selection For ◽

Prolonged Dormancy

Absence or long delay of budbreak, also known as prolonged dormancy, is the most important symptom during incomplete dormancy. Budbreak number was evaluated to quantify seedling response to chilling and selection on excised and intact 1-year-old apple (Malus ×domestica Borkh.) seedlings under controlled and natural environmental conditions. Indices based on: 1) the number and distribution of budbreak (prolonged dormancy grade = PDG); 2) the number of buds breaking, including shoot length with increased budbreak as part of the calculation (prolonged dormancy index = PDI); and 3) budbreak number per 100-cm shoot (NB) were tested in association with budbreak time (TB). The indices expressed the effects of cold treatments that induce earlier and higher numbers of budbreak. PDI and NB, but not PDG, identified families with increased budbreak. Seedlings with high PDG and NB were also associated with families in which high chill requiring parents were used, indicating that TB as pre-selection criterion may fail to identify seedlings with increased budbreak. Response to pre-selection for increased budbreak using PDG could be verified with the PDS and NB indices in seedlings and seedling clones. The NB of intact 1-year-old shoots under natural conditions is recommended as a pre-selection criterion against prolonged dormancy in suboptimal winter conditions.

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Effects of shearing 2 breeds of dairy ewes during lactation under mild winter conditions

Journal of Dairy Science ◽

10.3168/jds.2018-15380 ◽

2019 ◽

Vol 102 (2) ◽

pp. 1712-1724 ◽

Cited By ~ 1

Author(s):

A. Elhadi ◽

A.A.K. Salama ◽

X. Such ◽

E. Albanell ◽

P.G. Toral ◽

...

Keyword(s):

Mild Winter ◽

Dairy Ewes ◽

Winter Conditions

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Foliar photochemical processes and carbon metabolism under favourable and adverse winter conditions in a Mediterranean mixed forest, Catalonia (Spain)

Biogeosciences ◽

10.5194/bg-11-5657-2014 ◽

2014 ◽

Vol 11 (20) ◽

pp. 5657-5674 ◽

Cited By ~ 7

Author(s):

D. Sperlich ◽

C. T. Chang ◽

J. Peñuelas ◽

C. Gracia ◽

S. Sabaté

Keyword(s):

Quantum Yield ◽

Photosystem Ii ◽

Tree Species ◽

Cold Period ◽

Summer Drought ◽

Mild Winter ◽

Fluorescence Measurements ◽

Winter Conditions ◽

Evergreen Tree ◽

Wide Range

Abstract. Evergreen trees in the Mediterranean region must cope with a wide range of environmental stresses from summer drought to winter cold. The mildness of Mediterranean winters can periodically lead to favourable environmental conditions above the threshold for a positive carbon balance, benefitting evergreen woody species more than deciduous ones. The comparatively lower solar energy input in winter decreases the foliar light saturation point. This leads to a higher susceptibility to photoinhibitory stress especially when chilly (< 12 °C) or freezing temperatures (< 0 °C) coincide with clear skies and relatively high solar irradiances. Nonetheless, the advantage of evergreen species that are able to photosynthesize all year round where a significant fraction can be attributed to winter months, compensates for the lower carbon uptake during spring and summer in comparison to deciduous species. We investigated the ecophysiological behaviour of three co-occurring mature evergreen tree species (Quercus ilex L., Pinus halepensis Mill., and Arbutus unedo L.). Therefore, we collected twigs from the field during a period of mild winter conditions and after a sudden cold period. After both periods, the state of the photosynthetic machinery was tested in the laboratory by estimating the foliar photosynthetic potential with CO2 response curves in parallel with chlorophyll fluorescence measurements. The studied evergreen tree species benefited strongly from mild winter conditions by exhibiting extraordinarily high photosynthetic potentials. A sudden period of frost, however, negatively affected the photosynthetic apparatus, leading to significant decreases in key physiological parameters such as the maximum carboxylation velocity (Vc, max), the maximum photosynthetic electron transport rate (Jmax), and the optimal fluorometric quantum yield of photosystem II (Fv/Fm). The responses of Vc, max and Jmax were highly species specific, with Q. ilex exhibiting the highest and P. halepensis the lowest reductions. In contrast, the optimal fluorometric quantum yield of photosystem II (Fv/Fm) was significantly lower in A. unedo after the cold period. The leaf position played an important role in Q. ilex showing a stronger winter effect on sunlit leaves in comparison to shaded leaves. Our results generally agreed with the previous classifications of photoinhibition-tolerant (P. halepensis) and photoinhibition-avoiding (Q. ilex) species on the basis of their susceptibility to dynamic photoinhibition, whereas A. unedo was the least tolerant to photoinhibition, which was chronic in this species. Q. ilex and P. halepensis seem to follow contrasting photoprotective strategies. However, they seemed equally successful under the prevailing conditions exhibiting an adaptive advantage over A. unedo. These results show that our understanding of the dynamics of interspecific competition in Mediterranean ecosystems requires consideration of the physiological behaviour during winter which may have important implications for long-term carbon budgets and growth trends.

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