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Wang Thong, Thailand

Jairin J.,Ubon Ratchathani Rice Research Center | Sansen K.,Ubon Ratchathani Rice Research Center | Wongboon W.,Ubon Ratchathani Rice Research Center | Kothcharerk J.,Phitsanulok Rice Research Center
Breeding Science | Year: 2010

The brown planthopper (BPH) resistance gene bph4 has previously been assigned on the short arm of rice chromosome 6. However, the map position of the gene could not be determined. To detect the bph4 locus, 15 polymorphic simple sequence repeat (SSR) markers covering genetic distance of 0.0-63.4 cM on chromosome 6 were used to survey 15 BPH resistant (R) and susceptible (S) individuals from each of the 95 and 78 F2 populations derived from crosses of TN1/Babawee and Babawee/KDML105, respectively. One SSR marker, RM586, was associated with the R and S from the F2 populations. Additional markers surrounding the RM586 locus were examined to define the location of bph4. From the genetic linkage map and QTL analysis of 95 and 78 F2 individuals, the bph4 locus was mapped at the same chromosomal region of Bph3 between two flanking markers RM589 and RM586. Markers linked to the resistance gene explained 58.8-70.1% of the phenotypic variations and can be used for marker-assisted selection in BPH-resistant breeding programs. In addition, our experiment provides evidence that a recessive gene could behave as a dominant gene under different genetic backgrounds.

Korinsak S.,Kasetsart University | Siangliw M.,Kasetsart University | Kotcharerk J.,Phitsanulok Rice Research Center | Jairin J.,Ubon Ratchathani Rice Research Center | And 5 more authors.
Field Crops Research | Year: 2016

Shifts in weather patterns and increases in the frequency and magnitude of extreme weather events resulting from unfavorable climate change have led to frequent flooding and brown planthopper outbreaks in rice fields, particularly those in rainfed lowland areas in Thailand. The traditional jasmine rice cultivar KDML105, which is popularly grown in rainfed lowland areas in north and northeast Thailand, is intolerant to flash flooding and is very susceptible to the brown planthopper. Two major QTL, Sub1 and Qbph12, were individually introgressed from two donors into KDML105 using the marker-assisted backcrossing method. In this study, we have pyramided Sub1 and Qbph12 in the genetic background of KDML105 via marker-assisted selection coupled with stringent phenotypic selection for plant type and physical grain quality traits. In total, sixty-four pyramid lines (PLs) were developed and characterized for submergence tolerance, brown planthopper resistance, important agronomic traits and physical and chemical grain quality. Evaluation of the PLs indicated their significantly enhanced submergence tolerance and brown planthopper resistance compared with the original KDML105 line. All PLs satisfied the KDML105 grain and cooking quality standards, although their agronomic characteristics showed significant variations in days to flowering, plant height and grain yield. These variations might allow breeders to select new versions of KDML105 that are suitable for different locations in rainfed lowland environments. © 2015 Elsevier B.V..

Srisuwan S.,Khon Kaen University | Arkaravichien T.,Khon Kaen University | Mahatheeranont S.,Chiang Mai University | Puangsombat P.,Chiang Mai University | And 3 more authors.
Tropical Journal of Pharmaceutical Research | Year: 2015

Purpose: To investigate the antioxidative and memory-enhancing effects of aqueous extract of unpolished Thai rice strain of Luem Pua (LP) in SK-N-SH cells and scopolamine-induced memory deficit in mice. Methods: In SK-N-SH cells, viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay while intracellular reactive oxygen species (ROS) levels were quantified after pretreatment with LP (0, 200, 600 and 1000 μg/mL) in the presence of hydrogen peroxide (H2O2). In mice, memory was impaired by injecting 2 mg/kg/day scopolamine, for 18 consecutive days. On each day, mice were also force-fed with LP 0, 90 or 180 mg/kg. On the last 5 days of treatment, memory was tested using passive avoidance (PA) and Morris water maze (MWM) tests. Results: At concentration up to 1,000 μg/mL LP had no effect on SK-N-SH cell viability and significantly reduce intracellular ROS levels of SK-N-SH cells with or without H2O2. Mice that received 90 or 180 mg/kg LP showed a significant decrease in latency time in PA test and an increase in escape latency time in MWM test. These data suggest that LP antagonizes the effect of scopolamine on memory. Conclusion: LP extract has anti-oxidative and memory-enhancing effects in cell culture and mice. The rice may be a nutraceutical helpful for promoting brain health. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved.

Phothi R.,Naresuan University | Umponstira C.,Naresuan University | Sarin C.,Naresuan University | Siriwong W.,Naresuan University | Nabheerong N.,Phitsanulok Rice Research Center
Australian Journal of Crop Science | Year: 2016

This research investigated the effects of elevated ozone and carbon dioxide on photosynthesis of rice (Oryza sativa L.) cultivar Khao Dawk Mali 105. Seedlings were kept in indoor climate control chambers which were set to typically background level of ozone (<10 ppb) by passing inlet air from outside through charcoal filter prior to enter to the chambers. Plant samples were fumigated by ozone concentration level at 40 ppb, 70 ppb and carbon dioxide concentration level at 700 ppm. For combined effects, elevated carbon dioxide concentration 700 ppm was given into two combination treatments of ozone concentration level at 40 and 70 ppb. Control groups were grown in charcoal-filter chambers with no additional ozone. Plant samples then were fumigated with ozone and carbon dioxide for 28 days at tillering stage (at the rice age of 42 to 70 days), and analyzed weekly for photosynthesis rate, leaf chlorophyll, total soluble sugar and biomass. The results showed that ozone significantly caused reduction in photosynthesis, leaf chlorophyll, total soluble sugar and total biomass of rice. The ozone concentration level of 70 ppb significantly (p ≤ 0.05) affected rice more than 40 ppb treatment. Nevertheless, elevated carbon dioxide reduced the negative effects of ozone from both ozone concentration levels. Moreover, higher photosynthesis was observed in combined treatment, when compared with the control group. Finally, increasing of ozone caused reduction in rice photosynthesis; however, elevated carbon dioxide could significantly adverse the effects of ozone.

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