3 results
Evaluating a heat-tolerant wheat germplasm in a heat stress environment
- Sittichai Lordkaew, Narit Yimyam, Anupong Wongtamee, Sansanee Jamjod, Benjavan Rerkasem
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- Journal:
- Plant Genetic Resources / Volume 17 / Issue 4 / August 2019
- Published online by Cambridge University Press:
- 08 February 2019, pp. 339-345
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Heat stress, a regular risk to wheat in the subtropics, is a growing threat in other wheat producing regions as the global temperature rises. This paper reports on three experiments evaluating 49 entries of the 13th High Temperature Wheat Yield Trial (13HTWYT) from the International Centre for Maize and Wheat Improvement (distributed in 2014), with Fang 60 as the local check, at two locations at Chiang Mai, Thailand, a designated representative of the wheat mega-environment 5, in which temperature for the coolest month averages >17.5 °C and the crop is subjected to high temperature for the entire growing season. The wheat was grown in the lowland (elevation 330 m) at Chiang Mai University in (i) sand culture to simulate the condition of non-limiting nutrient and water supply and (ii) in the field and (iii) as an on-farm trial in the highlands (elevation 800 m) at Mae Wang district of Chiang Mai province. Heat tolerance in the wheat germplasm, recently developed for adaptation to high temperature, was indicated by longer pre-heading duration, and the positive correlation between days to heading and grain yield all three experiments. The longer time before heading enabled development of larger spikes that produced more seeds from more and larger spikelets and more competent florets. However, with the number of spikes that was either lower than or similar to Fang 60, none of the recently developed 13HTWYT entries out-yielded the local check from the 1970s.
Genotypic variation in adaptation to soil acidity in local upland rice varieties
- Suwannee Laenoi, Nattinee Phattarakul, Sansanee Jamjod, Narit Yimyam, Bernard Dell, Benjavan Rerkasem
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- Journal:
- Plant Genetic Resources / Volume 13 / Issue 3 / November 2015
- Published online by Cambridge University Press:
- 11 September 2014, pp. 206-212
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Local upland rice germplasm is an invaluable resource for farmers who grow rice on acidic soils without flooding that benefits wetland rice. In this study, we evaluated the adaptation to soil acidity in common local upland rice varieties from an area with acidic soil in Thailand. Tolerance to hydrogen and aluminium (Al) toxicity was determined by measuring root growth, plant dry weight and phosphorus (P) uptake in aerated solution culture without the supplementation of Al (0 mg/l) at pH 7 and 4 and with the supplementation of 10, 20 and 30 mg Al/l at pH 4. The root growth of upland rice plants grown from farmers' seed was depressed less by Al than that of common wetland rice varieties. Pure-line genotypes of upland rice varieties were differentiated into several classes of Al tolerance, with frequency distribution of the classes that sometimes differed between the accessions of the same varieties. The effect of Al tolerance on root length was closely correlated with depression by Al in root dry weight and whole-plant P content. A source for adaptation to soil acidity for exploitation in the genetic improvement of aerobic and rainfed rice is clearly found among local upland rice varieties grown on acidic soils. However, the variation in tolerance to soil acidity within and among the seed lots of the same varieties maintained by individual farmers as well as among the varieties needs to be taken into consideration.
2 - Gene flow, biodiversity, and genetically modified crops: Weedy rice in Thailand
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- By Barbara Schaal, Washington University, Wesley J. Leverich, St. Louis University, Sansanee Jamjod, Chiang Mai University, Chanya Maneechote, Chiang Mai University, Anbreen Bashir, St. Louis University, Amena Prommin, Chiang Mai University, Adirek Punyalue, Chiang Mai University, Athitya Suta, Chiang Mai University, Theerasak Sintukhiew, Sintukhiew, Anupong Wongtamee, Chiang Mai University, Tonapha Pusadee, Chiang Mai University, Sunisa Niruntrayakul, Chiang Mai University, Benjavan Rerkasem, Chiang Mai University
- Edited by J. Andrew DeWoody, Purdue University, Indiana, John W. Bickham, Purdue University, Indiana, Charles H. Michler, Purdue University, Indiana, Krista M. Nichols, Purdue University, Indiana, Gene E. Rhodes, Purdue University, Indiana, Keith E. Woeste, Purdue University, Indiana
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- Book:
- Molecular Approaches in Natural Resource Conservation and Management
- Published online:
- 05 July 2014
- Print publication:
- 14 June 2010, pp 35-49
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Summary
The domestication of plants and animals and the development of agriculture some 10,000 years ago has led to profound changes in the environment and to biodiversity (Diamond 1997; Smith 1998). As natural communities were replaced by pastures and fields, native species were displaced or their habitats fragmented (Heywood 1995; Millennium Ecosystem Assessment 2005). The extirpation of native species began with the earliest agricultural communities in the Middle East and Asia and continues today. Every major advance in agriculture, from the development of new crops to mechanized farming, has environmental consequence. The most recent change in agricultural practice is the planting of genetically modified (GM) crops. First developed and legalized in the 1990s, today the majority of crops in the United States are GM, with approximately 90% of the U.S. soybean crop GM for herbicide tolerance (U.S. Department of Agriculture 2008).
GM crops are varieties that have been transformed by using a biological or physical method to insert specific genes into a genome (Chrispeels & Sadava 2003). The inserted genes, transgenes, can come from another species or from the same species. In contrast, most varieties of nontransgenic crops are produced by traditional and modern methods of crop improvement and selective breeding (Chrispeels & Sadava 2003). Other descriptions for such GM crops are recombinant or genetically engineered crops. The specific methods of genetic manipulation used to produce a GM crop are not thought to have any serious consequences (National Research Council 2002), but rather the consideration of most concern is the specific nature of the introduced transgene. Because the method of crop improvement has little effect, some researchers have argued that the distinction between GM crops and non-GM crops is artificial; crops produced by traditional means of plant breeding are also GM (Federoff & Brown 2004). This point is important: The issues and concerns that have been raised about recently developed GM crops are also of concern regarding traditional crop varieties.