129 research outputs found
Germination of primed seed under NaCl stress in wheat.
Copyright © 2012 Michael P. Fuller et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Soil salinity affects a large and increasing amount of arable land worldwide, and genetic and agronomic solutions to increasing salt tolerance are urgently needed. Experiments were conducted to improve wheat seed performance under salinity stress conditions after priming. An experiment was conducted using a completely randomized design of four replications for germination indices in wheat (Triticum aestivum L. cv. Caxton). Normal and primed seed with PEG6000 at −1MPa and five concentrations of NaCl (0, 50, 100, 150, and 200mM) were tested. Results indicate that priming seed significantly (P < 0.05) increased germination percentage at first count and final count, coefficient of velocity of germination, germination rate index, and mean germination time, while increasing of NaCl concentration significantly reduced it. Priming seed improved germination attributes at all NaCl concentration levels. The priming appeared to be able to overcome the effect of salt stress at 50 to 100mMand reduce the effect of NaCl at higher concentrations up to 200 mM. The primed seed gave both faster germination and led to higher germination when under salt stress. We conclude that using priming techniques can effectively enhance the germination seed under saline condition
Encapsulation of cauliflower (Brassica oleracea var botrytis) microshoots as artificial seeds and their conversion and growth in commercial substrates
An effective protocol for the mass production of cauliflower microshoots was refined using the meristematic layer of cauliflower curd. After the meristematic layer was surface sterilized and shaved off, a commercial blender was used for homogenization and several blending treatments were tested in the range 15-120 s and 30 s was found to be optimal in terms of the amount explants produced and their subsequent growth ability. Explants were cultivated in S23 liquid medium (4.4 g L-1 MS (Murashige and Skoog) and 3% v/w sucrose) supplemented with several combinations of plant growth regulators (PGRs) including 1 and 2 mg L-1 of Kinetin in combination with three types of auxins (indole butyric acid (IBA), Naphthaleneacetic acid (NAA) and Indole-3-acetic acid (IAA)), each at 1 and 2 mg L-1 concentration. The use of 2 mg L-1 Kinetin and 1 mg L-1 IBA gave the best results in terms of its effects on explant induction. Microshoots of different sizes were encapsulated in a sodium alginate matrix and the optimal stage suitable for the production of artificial seeds was assessed in terms of both subsequent conversion and plantlet viability. The feasibility of cultivating cauliflower artificial seeds in commercial substrates (compost, vermiculite, perlite and sand) irrigated with different solution mixtures including sterilized distilled water (SDW), PGRs-free S23 medium and S23 medium supplemented with Kinetin (1 and 2 mg L-1) and IBA or NAA at (1 and 2 mg L-1) was investigated. The use of 2 mg L-1 Kinetin and 2 mg L-1 NAA applied with S23 gave the optimal response with both perlite and compost. This study showed high growth capacity of cauliflower artificial seeds in commercial substrates which is considered a promising step for their direct use in vivo. © 2011 Springer Science+Business Media B.V
Artificial Seed Production from Encapsulated Microshoots of Cauliflower (Brassica oleraceae var botrytis)
A cost effective protocol for the production of cauliflower microshoots suitable for encapsulation was designed. Microshoots were encapsulated in sodium chloride matrices. The use of 2% of sodium alginate and 15 g/L of dehydrate calcium chloride produced the optimal quality of artificial seeds (rigidity, conversion rate and viability). Of the various plant growth regulator combinations used with the microshoot liquid culture medium, the use of 1 mg/L of IBA (indole butyric acid) and 1 mg/L Kinetin was found to be optimal in terms of the conversion rate and viability of artificial seeds. To standardize a medium composition of artificial endosperm of synthetic seeds, different concentrations and combinations of plant growth regulators with S23 (4.4 MS + 30 g/L sucrose) medium were used in the beads to achieve optimum conversion rate and viability on an in-vitro medium. Whilst several combinations of plant growth regulators gave a conversion rate up to 100% (for example (0.5 mg/L Kinetin + 0.5 mg/L IBA), (1 mg/L Kinetin + 0.5 mg/L NAA (naphthaleneacetic acid)) and (1 mg/L Kinetin + 1 mg/L IAA (indole-3-acetic acid)), no significant effect on the viability of artificial seeds was found when these combinations were used. Artificial seeds were cultivated in a semi-solid medium containing several types and concentrations of auxin, 2 mg/L of IBA gave the best results in terms of artificial seed viability. However, artificial seed conversion rate was not significantly affected by the auxins and full conversion rate was obtained using many different treatments. This research indicated the feasibility of using artificial seeds as a promising alternative to seeds produced by traditional methodology
The Characterisation of the Freezing Damage Response during Flowering in European and Middle Eastern Wheat Cultivars (Triticum aestivum L)
Merged with duplicate record (10026.1/1553) on 03.01.2017 by CS (TIS)Wheat (Triticum aestivum L.) is occasionally exposed to low temperature during flowering and huge economic losses can occur especially in some key production countries such as Australia. Although it is generally predicted that there will be a rise in global temperature there are still predicted to be risks associated with low temperature for temperate crops. Post head emergence frost damage remains a major constraint to increasing wheat production.
Five Iraqi varieties (Abu-Ghariab, Fatah, Sham6, IPA95 and IPA99) were screened for their frost hardiness (LT50). Abu-Ghariab was chosen for further investigations along with the European cv. Claire because the acclimated frost hardiness level in these two varieties (LT50 -8.07 and -8.01°C for Claire and Abu-Ghariab respectively) was found to be significantly lower than the other varieties in this study.
Several techniques were employed including REC%, IR thermography and molecular analysis of cold acclimation in order to characterise the frost resistance of those two varieties. REC% revealed that both Claire and Abu-Ghariab could tolerate some freezing when the spikes were just visible (ZCK 51-60) with an acclimation shift of the LT50 of -1.6 and -2.11°C respectively but this was not apparent at later growth stages. Based on molecular analysis, cold acclimation was shown to be activated at ZCK 51-60 in both varieties. Cbf14 was expressed after 8 hours exposure to acclimatising temperatures (4°C) and then declined to a low, but still up-regulated level in both varieties and this led to expression of the COR15a protein. These molecular changes correlated with the frost tolerance recorded at ZCK 51-60. It was concluded that the possibility existed to up-regulate cold acclimation after spike emergence if there was enough environmental stimulus.
Molybdenum (Mo) was demonstrated to work synergistically with low temperature in increasing the expression of Cbf14 and COR15a. The European wheat cv. Claire showed a higher capacity (-8.14°C) to be acclimated than Iraqi wheat (-7.40°C) under the effect of both Mo and acclimation temperatures. Mo alone increased the expression of Cbf14 in both varieties but did not increase the frost tolerance.
Observations of ice nucleation using an infrared thermography (IR) revealed that supercooling is highly likely in spikes and some spikes avoided frost damage even when the temperature fell to -12°C. It was observed that the proportion of frozen spikes was 22.8% while the remainder supercooled. Spraying plants with distilled water was not effective in facilitating ice nucleation in wheat spikes. Observations also revealed that spikes that did freeze started freezing at temperatures of -4 to -5 °C close to temperature of the putative constitutive frost hardiness of un-acclimated wheat and it is suggested that this may reflect that many laboratory freezing experiments may not actually freeze until -5°C. The anthesis stage of wheat was found to be the most vulnerable stage and it needs to be given more attention in terms of research to up-regulate cold acclimation. Frost damage to wheat during flowering continues to be a serious problem in certain production areas and therefore continued effort in characterising and finding suitable solutions to this are imperative.Ministry of Higher Education and Scientific Research-Iraqi Embassy/Cultural attache-Londo
Exogenous application of molybdenum affects the expression of CBF14 and the development of frost tolerance in wheat.
Wheat is able to cold acclimate in response to low temperatures and thereby increase its frost tolerance and the extent of this acclimation is greater in winter genotypes compared to spring genotypes. Such up-regulation of frost tolerance is controlled by Cbf transcription factors. Molybdenum (Mo) application has been shown to enhance frost tolerance of wheat and this study aimed to investigate the effect of Mo on the development of frost tolerance in winter and spring wheat. Results showed that Mo treatment increased the expression of Cbf14 in wheat under non-acclimating condition but did not alter frost tolerance. However, when Mo was applied in conjunction with exposure of plants to low temperature, Mo increased the expression of Cbf14 and enhanced frost tolerance in both spring and winter genotypes but the effect was more pronounced in the winter genotype. It was concluded that the application of Mo could be useful in situations where enhanced frost resistance is required. Further studies are proposed to elucidate the effect of exogenous of applications of Mo on frost resistance in spring and winter wheat at different growth stages
Estimation of Maximum Shear Capacity of RC Deep Beams Strengthened by NSM Steel Bars
يهدف هذا البحث الى تخمين تحمل القص الاقصى للعتبات الخرسانية المسلحة العميقة والمقواة بتقنية التقوية قرب السطح باستخدام قضبان الحديد. من خلال اقتراح معادلة نصف وضعية بالاعتماد على نتائج مختبرية مع الاخذ بنظر الاعتبار مجموعة من المتغيرات المهمة و المؤثرة على سلوك هكذا عتبات مثل نسبة ذراع القص الى العمق الفعال (a/d ratio), مقاومة الانضغاط للخرسانة, زاوية ميل القضبان المطمورة, قطر تلك القضبان والمسافات بينها. لذا تم فحص ثلاثة عشر نموذج من الاعتاب الخرسانية المسلحة ذات نسب ذراع قص الى العمق الفعال مختلفة (a/d= 0.85, 1.136 and 1.42) . اذ تم تقسيم النماذج الى ثلاثة مجاميع اعتمادا على نسبة (a/d) وكل مجموعة تتكون من نموذج واحد غير مقوى كنموذج سيطرة واخرى مقواة بأساليب مختلفة من قضبان الحديد المطمورة قرب السطح. عند مقارنة النتائج المحسوبة والنتائج العملية وجد ان هناك تطابق جيد بينهما وبمعامل تحديد عالي يساوي (95.4%), ولتأكيد جودة الصيغة المقترحة في تقدير قدرة القص فقد تم استخدامها لتقدير تلك القيمة لعينات موجودة في بعض البحوث السابقة. حيث تم الحصول على توافق جيد في تخمين تحمل القص مع القيم العملية في تلك البحوث مع معامل تغاير (COV) منخفض.This work aims to estimate the maximum shear capacity of deep beams RC members strengthened by Near-Surface Mounted (NSM) steel bars. This is done by using an assumed semi-empirical formula that depends on experimental tests. This formula will cover many principal parameters such as shear span to effective depth ratios (a/d), orientation angle of NSM steel bars, concrete compressive strength (f′c), bar’s diameter and their spacing. So, thirteen reinforced concrete deep beams with different (a/d) ratios equals (0.85, 1.136 and 1.42) were tested. These beams are categorized into three groups depending on (a/d) ratio, which contained one unstrengthen beam as a control specimen and others strengthened beams by different schemes of NSM steel bars.
A comparison between the calculated and experimental values shows good agreement with high coefficient of determination (R2=95.4%). The proposed formula is also used to estimate shear capacity of some specimens that found in some previous literatures to confirm the validity of the formula in estimating shear capacity of different cases. Good agreement with low (COV) of the predicted shear capacity with the experimental values that found in literatures was obtained
The Features of Artistic Expression in Drawings of Children of the Sons of Artists and Chidren of Non-artists(Acomparative Study)
يتضمن البحث الحالي دراسة (سمات التعبير الفني في رسوم الاطفال من ابناء الفنانين وغير الفنانين)، دراسة مقارنة في محاولة للكشف عن سمات تلك الرسوم والوقوف على الخصائص التي تميزت بها وايضاح الاراء التي فسرت والقت الضوء على رسوم الاطفال والى بيان المداخل والخصائص التي تميزت بها رسوم الطفل، اضافة الى بيان اثر الاسرة على سمات التعبير الفني. وقد تكمن اهمية البحث الحالي والحاجة اليه بمحاولة التعرف على سمات رسوم ابناء الفنانين عن اقرانهم من الاطفال ابناء غير الفنانين،ليدعم معرفتنا في محاولة لوضع مفاهيم بحثية جديدة مما يتيح للمتلقي الاطلاع على السمات المتفردة في تعبيرهم الفني.
وقد تناولت الباحثة اسلوب البحث العلمي لمعرفة نتائج البحث واتخذت المقابلة طريقا لها، بوصفها اداة للبحث فضلا عن الملاحظة الميدانية، وحددت الباحثة مجتمع بحثها عينات اختارتها بطريقة عشوائية من ابناء استاذة كلية الفنون الجميلة في جامعة بابل ونماذج من تلاميذ المدارس الابتدائية والرياض في مركز محافظة بابل ايضا، في محاولة للاجابة عن الاسئلة المعدّة لذلك الغرض وقد توصلت الباحثة الى ان لابد من وجود فروق ذات دلالة معنوية في مجال الرسم التجريدي مما يدل على الجرأة في الطرح لدى الاطفال من ابناء الفنانين، كما وجدت فروق اخرى ذات دلالة معنوية في رسوم الاطفال من ابناء الفنانين من ناحية التحريف في الزمان والمكان مما يدل على امتلاكهم الخيال الواسع ومرونة طرح الافكار وفي ضوء نتائج الدراسة اوصت الباحثة بمجموعة توصيات وامتداداً لهذه الدراسة واستكمالا لها طرحت الباحثة مجموعة من الاقتراحات.The current research includes study the characteristics of artistic expression in drawings of children of the sons of artists and non-artists studied comparative in an attempt to reveal the features of those drawings and stand on characteristics' that characterized them and clarifying the views that shed light on the drawings of children and to indicate the entrances and characteristics that characterize the child's drawings add a statement to the effect of the effect of the family on the attributes of artistic expression the importance of the current research may lie in the need for it trying to identify the features of drawings artists sons about their peers from the children of non-artists which supports our knowledge in an attempt to develop new research concepts allowing the recipient to see the unique features of their artistic expression the researcher dealt with the method of scientific research to know the search results and have taken the corresponding method for them as a tool as well as an observation field the researcher identified a research community randomly selected samples from the sons of his professors of the faculty of fine Arts at the university of Babylon and models of primary school pupils and Riyadh in the center of the province of Babylon also try to answer the questions prepared for that purpose the researcher concluded that there must be significant differences in the field of abstract painting ,which indicates the boldness in the subtraction children have sons of artists other differences were found to be significant in children's drawings the distortion of time and place is assign of having a wide imagination and the flexibility of ideas and in light of the results of the study the researcher pointed out a total of recommendation and the ettension of this study and the completion of the researcher put it asset of suggestions
Plant abiotic stress tolerance analysis in cauliflower using a curd micropropagation system
An effective protocol for cauliflower micropropagation was optimised and developed which enabled the production of tens of thousands of cauliflower microshoots from one cauliflower curd. The large number of microshoots that can be produced per culture unit facilitates the use of this protocol to analyse both the physiological and molecular components of abiotic stress tolerance. The protocol was used for cauliflower cold tolerance analysis and it was demonstrated that low temperature acclimation increased the cold tolerance of explants. The effect of two additives used with the cauliflower culture media on cold tolerance were evaluated. ABA significantly decreased both cold tolerance in acclimated and non-acclimated cauliflower microshoots whilst molybdenum had a highly positive effect on cold tolerance of cauliflower microshoots. Moreover, molybdenum had the capacity to increase the cold tolerance of cauliflower microshoots without low temperature treatment. This is the first study that confirmed this feature of molybdenum and it is believed that this finding could have an application in the field
- …