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adam barclay (4)After a 10-day flood, the Sub1 plantsrecovered well, while the Gayatriplants perished.According to CRRI DirectorT.K. Adhya, the release of floodtolerantrice has become more andmore important as India has growneconomically.“People used to grow rice in morefavorable areas, where you had anassured source of water and good soilquality,” he explains. “Now, thoseinterior areas are being taken overby human habitation and industry,so farmers are forced onto marginallands in the coastal areas whereflooding, salinity, and many otherproblems occur. In the past, farmerssimply had to face flooding and blametheir luck if they didn’t get a harvest.”IRRI plant physiologistAbdel Ismail, who is studying themechanism of SUB1A’s action, saysthere is a strong case for rapid releaseof the new varieties.“When you develop varietiesusing marker-assisted selection,” hesays, “you do not change the varietymuch. Because the SUB1A gene isvery specific in its expression andaction during submergence, the Sub1varieties should not have any otherproblems—such as susceptibilityto diseases or insects—that theirnontolerant counterparts wouldn’thave also. In the future, we expectExamining trials at BRRI headquarters in Gazipur, K.M. Iftekharuddaula (right) has bred flood toleranceinto popular Bangladeshi rice variety BR11, which accounts for more than one-third of the country’swet-season plantings.many new varieties to come outas products of MAS. If you have asubmergence-tolerant or salt-tolerantvariety, for example, you want it togo to the field as quickly as possible,where it can make a big difference.”N. Shobha Rani, principal scientistat India’s Directorate of Rice Research,says that traditionally bred rice mustundergo testing for 3 years in all-Indiatrials, but this has been reduced to 2years for MAS-derived varieties.“The second year of testing is2009,” says Dr. Rani, “so, April 2010is the earliest time the Sub1 varietiescould be recommended by the CentralVariety Release Committee fornational release.” She notes, however,that release could occur on a statebasis before then.In fact, on 27 February 2009,only a few months after Dr. Ranitalked to Rice Today, the UttarPradesh State Varietal ReleaseCommittee officially releasedSwarna-Sub1. Being nearly identical—apart from its flood tolerance—toSwarna, this inaugural release ofa Sub1 mega-variety occurred veryquickly: only 6 years after the firstcross was made at IRRI.A quick release is also possiblebecause plants developed throughMAS are not transgenic (that is,genes of interest are transferred tothe target species or variety usingparticular biotechnological toolsrather than conventional breeding).Therefore, the new Sub1 varieties areA patch of the popular rice variety Swarnalies flattened and dying after several days offlooding. In contrast, the flood-tolerant version,Swarna-Sub1, rebounds to good health.not subject to the regulatory testingthat can delay release of transgenicproducts for several years.The Sub1 trait also came alongwith an additional bonus, a genelinked to SUB1A that turns thenormally golden color of the hull ofSwarna into a straw color. Althoughthe hull color is not considered animportant varietal requirement,this allows the seeds of Swarna-Sub1 to be easily distinguishedfrom those of Swarna. This will beuseful to maintain seed purity asseed producers start ramping up theproduction of foundation seed fordistribution to farmers.Another success to emergefrom the Sub1 work has beenthe strengthening of nationalorganizations such as BRRI andCRRI.“In India now, MAS has a lot ofsupport from the government,” saysDr. Ismail. “In Bangladesh, BRRI hasits own lab for MAS, and not just forSUB1. In the national agriculturalresearch and extension systems, theproject has boosted capacity throughresources and expertise, and alsothrough government support.”BRRI researcher K.M.Iftekharuddaula is a good example.He carried out his Ph.D. researchunder Dr. Mackill’s supervision atIRRI headquarters in the Philippines,developing a flood-tolerant versionof popular Bangladeshi variety BR11,which accounts for more than onethirdof the country’s wet-seasonplantings. After completing his thesisresearch, he returned to Bangladesh,where he is now the BRRI breederresponsible for refining BR11-Sub1varieties for official release.“We are very much hopeful thatwe’ll be able to release at least twovarieties from our efforts,” says Mr.Iftekharuddaula, who is also workingwith IRRI to incorporate diseaseresistance and salinity tolerance intoBR11-Sub1.As Sub1 varieties are officiallyreleased over the next 2 years,the key will be dissemination tosmallholder farmers in flood-proneareas. IRRI is leading this initiativethrough the project Stress-TolerantRice for Poor Farmers in Africaand South Asia, funded by the Bill& Melinda Gates Foundation. IRRIis also collaborating with nationalorganizations to test Sub1 varieties inSoutheast Asian countries, includingLaos, Thailand, Cambodia, Indonesia,Vietnam, and the Philippines,through a project funded by Japan’sMinistry of Foreign Affairs.Dr. Ismail adds that SUB1A’seffectiveness offers hope for researchinto tolerance of other so-called abioticstresses, such as drought and salinity.“The general notion with abioticstresses used to be that it would bevery difficult to find a single gene thatcan make much difference,” he says.“This work has shown that you canget a single gene of great agronomicvalue. I think this has set the tone forsolving other major difficulties in thefield, such as problem soils.”The story of the SUB1 researchunderscores the capacity of scienceto improve people’s lives, as wellas the power inherent in a gene. Itseems a long and unlikely journeyfrom experimental plots in thePhilippines and the laboratorybenches in California to a small farmin Bangladesh.For Drs. Ronald and Bailey-Serres, the chance to get out of thelab and see the Sub1 varieties infarmers’ fields has been a profoundexperience.“It was amazing to see that thisdetailed genetic and physiologicalanalysis ultimately has potential for agrand impact on people who are oftenliving in pretty desperate situations,”Dr. Bailey-Serres says.Even Dr. Heuer, who, through herwork at IRRI, is no stranger to Asia’srice fields, has been moved. “I had noidea about the impact we can havebefore seeing it with my own eyes,”she adds. “I’ve learned about thepower of agricultural research here.I think it will have a huge impact.”Mr. Barclay is a freelance writerbased in Australia. See www.irri.org/flood-proof-rice.IRRI molecular biologist Sigrid Heuer (center) with her Ph.D. student Namrata Singh (left) and IRRIassistant scientist Darlene Sanchez at the Chinsurah Rice Research Station, in West Bengal, India.30 Rice Today April-June 2009Rice Today April-June 200931