scholarly journals Low Temperature Tolerance of Apple Shoots Following Exposure to Warm Temperatures in Late Winter

HortScience ◽  
2021 ◽  
pp. 1-10
Author(s):  
Renae E. Moran ◽  
Bryan J. Peterson ◽  
Gennaro Fazio ◽  
John A. Cline

The goal of this research was to evaluate resistance of apple rootstocks to late winter deacclimation during a 2-day exposure to warm temperatures in Maine. We measured the cold temperature tolerance of xylem, phloem, and cambium from 0 to −40 °C in 1- and 2-year-old shoot pieces from apple rootstock cultivars and advanced selections ‘M.9 T337’ (M.9), ‘M.7 EMLA’ (M.7), ‘Budagovsky 9’ (B.9), ‘Geneva® 41’ (G.41), ‘Geneva 30’ (G.30), ‘Geneva 935’ (G.935), ‘Geneva 814’ (G.814), G.4013, G.5257, and Vineland 6 (V.6) after a 2-day exposure to warm (22 °C) or cold (2 to 4 °C) temperatures. Injury was measured on a 0 to 10 rating scale based on percentage of discolored cross-sectional xylem and phloem, and cambial length and circumference with brown discoloration, with 0 indicating no browning and 10 indicating browning in the entire tissue. Injury was also measured as intensity of browning on a scale of 0 (no browning) to 5 (dark brown to black). The weighted averages of the two ratings were used to calculate an index of browning. Genotypic variation occurred in the degree of deacclimation, which ranged from none to as much as 15 °C loss in hardiness. Two genotypes, ‘G.41’ and ‘M.9’, showed little change in hardiness in both years they were tested. Two genotypes, G.4013 and ‘G.814’, lost substantial hardiness in both years and may be vulnerable to late winter freeze-thaw events, but were among the hardiest before deacclimation. ‘G.935’ and G.5257 showed a small loss of hardiness, whereas ‘B.9’ lost hardiness in the cambium, but not the xylem, and V.6 lost hardiness after warm exposure, but showed almost no injury at temperatures as cold as −35 °C. The loss of hardiness of these four genotypes that were tested in only one year should be verified with additional testing because of the potential for yearly variation.

2018 ◽  
Vol 143 (5) ◽  
pp. 319-332
Author(s):  
Renae E. Moran ◽  
Bryan J. Peterson ◽  
Gennaro Fazio ◽  
John Cline

To identify genotypes of apple (Malus ×domestica) rootstock with vulnerability to low temperature, we measured the low temperature tolerance of xylem, phloem and cambium in 2-year-old shoot pieces from cultivars Budagovsky 9 (B.9), M.7 EMLA (M.7), M.9 EMLA (M.9), Geneva® 41 (G.41), Geneva 30 (G.30), Geneva 214 (G.214), Geneva 814 (G.814), and Geneva 935 (G.935), as well as six advanced selections in the Geneva (G.) series and three in the Vineland (V.) series. From Oct. 2013 to Apr. 2014, injury was measured as a 0–10 rating based on percentage of discolored cross-sectional xylem and phloem, and cambial length and circumference with brown discoloration, with 0 indicating no browning and 10 indicating browning in the entire tissue. From Oct. 2014 to Apr. 2015, injury was measured as xylem, phloem and cambium browning using a similar rating scale that accounted for both the percentage of browned tissues and the intensity of browning. Following exposure to −35 to −40 °C, many genotypes, including ‘M.7’, ‘M.9’, ‘G.935’, G.4011, G.4292, G.5087, and V.5, had only partial xylem injury in the fall, whereas others, ‘M.7’, ‘G.41’, ‘G.214’, and G.4011, had more extensive xylem browning at −30 °C and colder. ‘G.30’ had moderate to severe xylem browning at −15 to −19 °C. In late October of both years, G.4013 exhibited severe phloem browning at relatively high temperatures, but accrued additional hardiness by Nov. 2014, whereas genotypes ‘B.9’, ‘M.9’, ‘G.30’, and ‘G.41’ developed considerable phloem hardiness by late October with no additional increase in hardiness in November. Geneva and Vineland genotypes exhibited a low degree of susceptibility to injury at −35 to −40 °C in Jan. 2014 and Mar. 2015. Shoot hardiness in Apr. 2014 and 2015 was highly variable between the 2 years, with severe browning of xylem and cambium at −40 °C in every genotype sampled in Apr. 2014, but not in Apr. 2015. ‘M.9’ and G.3902 appeared to be the least vulnerable to injury in April, whereas ‘G.30’, ‘G.41’, ‘G.814’, G.4292, and G.5257 seem more likely to suffer injury in spring. ‘G.30’ had tender xylem in both fall and spring, G.4013 had the least hardy cambium and phloem in fall, and G.5257 the least hardy cambium in the spring. These genotypes are vulnerable to damaging temperatures during fall acclimation and spring deacclimation.


2019 ◽  
Vol 99 (4) ◽  
pp. 510-524
Author(s):  
D.E.J. Wright ◽  
J.A. Cline ◽  
H.J. Earl

The use of drought-tolerant rootstocks is an important strategy in maintaining orchard productivity while meeting the increasing need to conserve water resources. The drought tolerance of two new genotypes, Vineland 1 (V.1) and Vineland 3 (V.3), was assessed along with industry standards to test the hypothesis that differences in water-use efficiency exist among these apple rootstocks. One-year-old, non-grafted nursery liners of M.9, MM.111, V.1, and V.3 were grown in a controlled-environment experiment. Plants of each genotype were maintained water-replete or were subjected to a 9-d controlled dry down and then maintained under water stress conditions for 55 d. Water stress reduced biomass accumulation and trunk cross-sectional area for all four genotypes. The two vigorous genotypes, MM.111 and V.1, increased their root-to-shoot ratios in response to water stress, whereas the root-to-shoot ratios of M.9 and V.3 remained unchanged in their water-replete controls. Genotype V.3 maintained its transpiration at a significantly lower soil water content compared to M.9, MM.111, and V.1. Of the four genotypes, V.3 demonstrated a high tolerance to water stress conditions, and therefore deserves further investigation using grafted apple trees in an orchard study.


1994 ◽  
Vol 8 (3) ◽  
pp. 201-212 ◽  
Author(s):  
Zora Raboteg‐šaric ◽  
Miomir Žužul ◽  
Gordana Keresteš

The aim of this study was to investigate whether, and how, extreme environmental influence, such as a war situation, can affect the development of children's aggressive and prosocial behaviour. A combined longitudinal–cross‐sectional design was used in the study. Subjects were preschool children whose behaviour was rated on the Children's Aggressive and Prosocial Behaviour Rating Scale (Žužul, Keresteš and Vlahović‐štetić, 1990) by their teachers. At the beginning of 1991 (before the war in Croatia started) the behaviour of two groups of children (one five years old and one six years old) was assessed. One year later, the younger group was assessed again. Another group of five‐year‐old children was also included and rated at the same time. Data were analysed according to age, sex and the time of measurements. The analyses of longitudinal data and cross‐sectional comparisons support the conclusion that the war had a strong impact on the development of prosocial behaviour. In this period, children's prosocial behaviour had increased, while aggressive behaviour had not changed. Results are discussed in terms of developmental changes and the effects of war on children's behaviour.


1998 ◽  
Vol 16 (4) ◽  
pp. 238-242 ◽  
Author(s):  
Steve McNamara ◽  
Harold Pellett

Abstract Laboratory freezing tests of stem hardiness were conducted to develop cold hardiness profiles for 18 weigela (Weigela sp.) cultivars during the fall and winter of 1994–95. Tests were performed on containerized plants held in a temperature-controlled greenhouse to prevent exposure to potentially lethal temperatures. No cultivar survived below −6C (21F) in the October 3 test. Subsequent differences in rates of acclimation resulted in cultivars differing in hardiness by as much as 13C (23F) on November 14. Taxa also differed greatly in their maximum midwinter low temperature tolerance with ‘Centennial’ and ‘Eva Supreme’ hardy to −44C (−47F) and −28C (−18F) in mid-January, respectively. None of the cultivars deacclimated substantially in response to a week of artificially-imposed diurnal freeze/thaw cycles in early February. Taxa with the greatest midwinter hardiness also maintained the greatest hardiness in early March. Overall, ‘Centennial’, ‘Java Red’, and ‘Samba’ were the most cold hardy cultivars tested, while ‘Boskoop Glory’, ‘Bristol Snowflake’, and ‘Variegata’ were the least hardy. Cold injury of susceptible weigela cultivars appears to be a consequence of late hardening and/or insufficient midwinter hardiness rather than rapid deacclimation in response to periods of warm temperatures in mid-to late-winter.


Author(s):  
Zoya Ozherelieva ◽  
Evgeny Sedov

AbstractArtificial freezing was used to evaluate diploid and triploid apple cultivars from the All Russian Research Institute of Fruit Crop Breeding at Orel throughout three winters. The studied apple varieties were developed by breeder E. N. Sedov and cytological analysis was carried out by cytologist G. A. Sedysheva. In early winter, all cultivars exhibited high tolerance to cold. In mid-winter buds and wood were severely damaged, while bark was more resistant for most cultivars. Basic components of hardiness were estimated: component I - frost resistance at -25 °C in the beginning of winter; component II - maximum value of frost resistance at -40 °C developed by plants during hardening; component III - ability to retain the hardened condition at -25 °C after a period of three-day thaw at +2 °C; and component IV - the ability to restore frost resistance at -30 °C after repeated hardening and three-day thaw at +2 °C. During late-winter thaws, buds suffered from frosts, while the bark and wood retained frost hardiness. Late in winter all cultivars demonstrated high resistance to repeated frosts. Triploid cultivars exhibited the highest level of cold hardiness of vegetative buds, bark and wood of annual shoots throughout the winter; these cultivars included ‘Zhilinskoye’, ‘Vavilovskoye’, ‘Osipovskoye’, ‘Patriot’, ‘Sinap Orlovski’, ‘Spasskoye’, ‘Turgenevskoye’, and diploids ‘Bolotovskoye’, ‘Sokovinka’, and ‘’Ranneye Aloye’.


2017 ◽  
Vol 4 (1) ◽  
pp. 436-441
Author(s):  
Saba Haider ◽  
Noman Ul Haq ◽  
Sohail Riaz ◽  
Aqeel Nasim ◽  
Muhammad Saood ◽  
...  

Objective: This study aimed to assess the knowledge and awareness regarding cervical cancer and its prevention among nurses working in different hospitals of Quetta, Pakistan. Methodology: The cross sectional, descriptive study was conducted by using structured questionnaire in different hospitals of Quetta from January to September 2016. Convenient sampling technique was applied by targeting all the nurses working in different hospitals of Quetta city. Study questionnaire was developed and tested for validity and reliability. Descriptive and inferential statistics (Mann Whitney U test and Kruskal Wallis tests, p<0.05) were used to assess the significance among study variables and were performed by using IBM SPSS v.20. Results: Out of 415 distributed questionnaires 324 were returned (response rate of 78%). The mean Age of respondents was 28.18 ±9.5 years. Majority (n=127, 43.3%) of participants were interns and had no or less than one year of experience (n=128, 43.7%) with negative family history of any cancer (n=275, 93.9%). Mean knowledge score was 18.52±4.84with majority (n=258, 88.1%) had adequate knowledge regarding cervical cancer. Respondent sage, current area of practice, qualification, Institute of degree and past family history were contributing factors (p > 0.05) in adequate knowledge in this study. The results also reviled that not only 68.3% (n=200) and 65.5% (n=192) respondents knew that cervical cancer is vaccine preventable and availability of the vaccine for it. Conclusions: Nurses working in different hospitals of Quetta city had better understanding of the disease cervical cancer and its prevention. Yet many of the respondent are not aware of it vaccine and its availability.


2020 ◽  
Vol 6 (2) ◽  
pp. 78-81
Author(s):  
Md Tauhidul Islam Chowdhury ◽  
Mohammad Shah Jahirul Hoque Chowdhury ◽  
Mohammad Sadekur Rahman Sarkar ◽  
KM Ahasan Ahmed ◽  
Md Nazmul Kabir ◽  
...  

Background: In evaluation of non-traumatic subarachnoid hemorrhage CT angiography (CTA) has 97-98% sensitivity and near 100% specificity. Objective: This study was conducted to evaluate the CTA findings of CT positive non traumatic subarachnoid hemorrhage. Methodology: This is an observational cross sectional study performed in Neurology department of National Institute of Neurosciences and Hospital, Dhaka over one year period (January 2019 to December 2019). Total 87 CT positive subarachnoid hemorrhage cases were purposively included in this study. All CT positive patients underwent CTA of Cerebral vessels for further evaluation. The angiography were evaluated by competent neuro-radiologists blinded about the study. Result: Among 87 patients, 40.2% were male and 59.8% were female. The average age was 53.33±11.1 years. Among the studied patient the source of bleeding was found 78.16% aneurysmal and 21.84% non-aneurysmal. 85.30% patients had single aneurysm and 14.70% had multiple aneurysm. The highest number of patient had Acom aneurysm (41.17%) followed by MCA (22.05%), ICA (13.23%), ACA (7.35%) and vertebral artery (1.14%) in order of frequency. Among the multiple aneurysm group most of the patients had combination of Acom, MCA and ICA aneurysm. Conclusion: From this study, we can conclude that CTA can be used as the primary diagnostic tool in evaluation of spontaneous SAH. Journal of National Institute of Neurosciences Bangladesh, 2020;6(2): 78-81


2012 ◽  
Vol 2 (2) ◽  
pp. 345-350
Author(s):  
Dr. Girish.L Dandagi ◽  
◽  
Venkat kalyana kumar. P ◽  
Dr. Dr.Isaac Mathew ◽  
Dr. Dr.G S Gaude Dr. Dr.G S Gaude

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