Pre-harvest sprouting is a major physiological problem in rice caused by prolonged rainfall and high humidity during the harvest period, and it is one of the most important targets in current rice breeding programs. In this study, the effect of cold and freezing storage on the pre-harvest sprouting rate was investigated using ten rice varieties under four different treatments. The result showed storage treatments of panicle samples used for germinate evaluation had no significant influence on the pre-harvest sprouting rate. These findings may enhance the efficiency of mass screening for pre-harvest sprouting and support the development of tolerant rice varieties.
Cold stress is one of the serious abiotic stresses for stable rice production especially in high-latitude temperate region and high-altitude tropical area. Improving cold tolerance at seedling stage led stable seedling growth with yield stability. In this study, QTLs for cold tolerance at seedling stage were identified using the 96 introgression lines (ILs) derived from an inter-specific cross between Hwaseong (
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Rice is a temperature-sensitive crop, its yield is severely affected by low temperature, especially cold stress at the seedling stage will delay heading. To understand the genetic basis of cold tolerance, we evaluated the cold tolerance at the seedling stage of 136 rice accessions. To evaluate cold tolerance, we treated rice seedlings with cold water irrigation for ten days and scored the cold tolerance on a 1-9 scale, based on their low-temperature response and subsequent recovery. The genome-wide association study for cold tolerance revealed seven QTLs on chromosomes 1, 3, 6, 7, 10, and 12. The genomic region of the
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Cold stress is an emerging threat for rice production in Bangladesh particularly in Boro season (winter rice) at seedling stage. Cold stress during seedbed stage or early establishment stage at the main field induces severe seedling mortality that increases cost cultivation and delays crop establishment and ultimately entails into low yield. Development of sustainable cold tolerant high yielding rice varieties warrants an efficient and economic screening technique of germplasms and breeding population. The protocols for cold screening that so far have been used by the breeders and reported in literature are generally dependent on natural cool temperature and/or expensive climate chamber. In this paper, we report an in-house screening protocol that requires less than three weeks to complete the screening cycle and can be used all year round for mass screening of breeding population.
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Maize (
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Low temperature stress at the seedling stage of rice is an important factor causing the leaf discoloration, wilting and consequently leads to non-uniform crop maturation. In order to screen the cold tolerance elite lines efficiently, the five cold treatment conditions with different water and air temperature were designed and treated at seedling stage. For the evaluation of seedling tolerance, the injury was scored by visual rate and measured by Soil and Plant Analyzer Development (SPAD) meter. In the reactions of varieties for each treatment, the treatment ‘B’ condition, 12ºC mean water with 24ºC mean air, shows clear discoloration, so it’s correlation coefficient was highest (r=−0.9,
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The differential expression of six basic helix-loop-helix (bHLH) genes in response to low temperatures was studied by evaluating their mRNA levels in the buds and shoots of grapevines. Comparison of the amino acid sequences deduced from nucleotide sequences of the bHLH genes in
The purpose of this study was to investigate responses of pear cultivars ‘Niitaka’ and ‘Chuwhangbae’ under short period heating on cold resistance level of flower buds. Experiment was conducted using annual shoots flower bud which were artificially heated (AH) during 72 hour at room condition (18–20°C). To assay for cold resistance, the cultivars were treated and observed under negative temperatures −10, −15, −20 and −25°C during the winter period in 2012 and 2013. Our findings revealed that ‘Chuwhangbae’ which was treated under control and artificial heating treatments was more resistant to low temperature than ‘Niitaka’ showing decreasing level of flower buds damages by mid-January although in early March an increasing level of damages was observed again. Cold resistant cultivar ‘Chuwhangbae’ responded more sensitively to external environments. This means that ‘Chuwhangbae’ restructures the plant protoplasts and process the transition to the new metabolic energy level in an efficient manner when triggered by effective negative temperatures thereby resulting in hardening process. We assume that this might be closely related with dormancy period, concentration of the mineral elements, water potential and transition processes of metabolism to the new energetic level. With a rise in temperature, cold tolerance in pear cultivars significantly decreased and this is related to intensive development of the floral organs. The chilling requirements for blossoming of ‘Niitaka’ was higher than ‘Chuwhangbae’.
A total of 23 elite rice cultivars from eight countries were evaluated for cold tolerance using two screening methods at Chuncheon Substation, National Institute of Crop Science (NICS), Republic of Korea. The rice cultivars Jinbu, Mustaqillik, and Avangard showed cold tolerance and high spikelet fertility (63–79%) in cold-water irrigation screening. Under greenhouse screening, five cultivars (Giza 177, Avangard, Mustaqillik, Jinbu, and Jungan) showed high cold tolerance and high spikelet fertility (71–81%). Simple sequence repeat (SSR) marker analysis of 21 genotypes revealed two major clusters, the
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Grape (
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Low-temperature stress is an important factor controlling the growth and development of rice (
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