1315-1415 H, Thursday, 18 October 2012
Havener Auditorium, IRRI
The unique event will review IRRI’s history with private sector engagement and discuss varying viewpoints on the future of PPP by our IRRI panel before opening the floor to the audience. Diverse perspectives are welcome!
Plant Breeding, Genetics, and Biotechnology Division Seminar
By Lutz Neumetzler
Visiting research fellow
Plant Breeding, Genetics, and Biotechnology Division
1400 H, Wednesday, 17 October 2012
Room A, D.L. Umali Building
Plant cell walls provide rigidity, shape the habitus of an organ, and, in turn, form the plant body. They are designed to fulfill a variety of functions, among them, water and nutrient transport in heights up to 100 meters, resisting enormous negative pressure. During the life of the plant, different phases such as cell division, cell expansion, and cell differentiation require the cell wall to be flexible, expandable, and strong at the same time. This is achieved by a dynamic interplay between cell wall-synthesizing glycosyltransferases located in the Golgi Apparatus and in the Plasmamembrane; and glycosylhydrolases that remodel and fine-tune cell wall structure in the apoplast. Plant cell walls are comprised mostly of carbohydrate polymers and are thus one of the biggest sink compartments in the plant body. These fixed energy and carbon resources can be used in sustainable ways. In order to ease saccharification or deconstruction of cell walls for, e.g., bioethanol production, we attempted to understand regulatory and developmental programs by modifying receptor-like kinases and transcription factors in planta. Within the European consortium initiative Knowledge Based Bio-Economy (KBBE), Arabidopsis and Brachypodium distachyon, an annual grass model species, were used in a study to compare cell wall metabolism in monocots and dicots.
By Fumitaka Shiotsu Lecturer Ibaraki University, Japan
1315-1415 H, Tuesday, 16 October 2012 Room A, D.L. Umali Building, IRRI
Steady increase of rice production warrants world food security in the future. However, improvements in rice yield potential have become stagnant recently not only in the tropics but also in Japan. In the seminar, we discuss the physiological characteristics of recent high-yielding varieties in Japan. In particular, we focus on the mechanisms responsible for varietal difference of the ripening (grain filling) ability. Our experiments showed that the "sink-source balance" was tightly linked to the ripening ability, and higher post-anthesis assimilation and stem reserves contributed to higher yield. We also found positive relationships between panicle morphology and ripening ability, suggesting that genetic control of panicle traits, at least in part, improves translocation efficiency and the ripening ability.
By Rodrigo Muñoz, Jr., dean, College of Engineering and Architecture, Maria Crizele de Jesus, electronics engineering student, and Graychelle Isidro, electronics and communications engineering student Bataan Peninsula State University
1315-1415 H, Thursday, 16 August 2012
Havener Auditorium, IRRI
A. Neighborhood effects and social behavior: The case of irrigated and rainfed rice farmers in Bohol, Philippines By Taku Tsusaka Postdoctoral fellow Social Sciences Division (SSD)
B. Preliminary study on behavioral game experiments By James Randall Simon Fraser University, Canada Intern, Social Sciences Division (SSD) 1530-1630 H, Wednesday, 11 July 2012 SSD Conference Room, Drilon Hall, IRRI
By Adrienne B. Nicotra Future fellow/associate professor Division of Evolution, Ecology, and Genetics Research School of Biology Australian National University, Canberra, Australia 1500 H, Wednesday, 4 July 2012 Room A, D.L. Umali Auditorium, IRRI
By Cécile Julia
Engineer in plant breeding; Ph.D. student in rice ecophysiology, CIRAD-AGAP, Montpellier, France Ph.D. research scholar, Crop Physiology Unit
Crop and Environmental Sciences Division (CESD), IRRI
1315-1415 H, Tuesday, 26 June 2012
Room A, D.L. Umali Auditorium, IRRI
Thermal stress and in particular heat during anthesis causes sterility in rice inflorescences. Rice spikelets open in the morning and close a few hours later. Genotypic variation in the time of day of anthesis is considered an escape mechanism from thermal stress, but little is known on its dependency on environmental conditions.
One traditional, cold-tolerant rice cultivar and three improved tropical rice cultivars were grown in the field in four different climatic environments under flooded conditions to study the environmental response of time of day of anthesis. The time of day when the first spikelets opened, a maximum of spikelets were open and the last spikelets closed was observed daily on a population basis (2m² plots replicated 3 times).
Within the same environment, genotypic differences in time of anthesis and duration of anthesis were small. Across all genotypes and environments, the differences were broader and 80% of the variation of the time of maximum anthesis could be explained with the mean minimum air temperature (Tmin) during the 7 days preceding any given anthesis event. Linear, multiple regression models determined for each cultivar using Tmin and vapor pressure deficit (VPD) observations from the three tropical environments explained 94% of variation of time of anthesis onset and end. Low Tmin thereby delayed and low VPD advanced anthesis processes.
Under the assumption that panicle temperature during anthesis is indeed a major determinant of spikelet fertility in rice, it is concluded that the sensitivity of time of day of anthesis to air temperature and humidity is an effective eco-physiological adaptation of the rice crop.
By Amelia Henry
Scientist, drought physiology
Crop and Environmental Sciences Division, IRRI
1315-1415 H (UTC + 8), Thursday, 14 June 2012
Havener Auditorium, IRRI
Abstract: Rice root growth encompasses a remarkable genetic diversity in terms of growth patterns, architecture, and environmental adaptations. Root/drought research at IRRI has been ongoing since the 1970s, with a long-term focus on root growth at depth and large nodal root diameter as drought resistance traits. After direct selection for yield during the past decade that is now approaching impact at the farm level, we are seeing that root traits are indeed involved in improved yield under drought. Surprisingly, traits other than deep root growth and large diameter nodal roots have been observed. This presentation will summarize the progress we have made in identifying root traits behind major-effect drought-yield QTLs in genotypes developed at IRRI.