Post-Green Revolution technologies
By the 1990s, stagnation of yield in rice was apparent with the HYVs, with the sd-1 gene for dwarfing having certain genetic limitations for further enhancement of yield potential. In order to keep pace with the growing population, the estimated rice requirement by 2025 is about 130 million tons. The plateauing of rice yields after the initial quantum jump with the first semidwarf varieties such as IR8 and Jaya and declining natural resources causing an impending water, land, and labor crises in the years to come made the task of enhancing rice production to the scale envisaged look insurmountable. Thus, the current alarming situation necessitated looking for some innovative technologies to boost rice production such as hybrid rice technology and rapid strides in harnessing the strengths of biotechnology.
Thus, the present Directorate of Rice Research (DRR) has been instrumental in successfully integrating two streams of research systems available under the central and state governments. It has extensively contributed to the development of appropriate rice varieties and production and protection technologies suitable for different seasons, conditions, and ecosystems and bringing in the much-needed gains to rice production. The unique concept of multi-location and multi-disciplinary testing with the underlying philosophy of cooperative effort in problem identification and action played a catalytic role in the adoption and spread of the first generation of HYVs and appropriate package of practices for varied ecosystems across the country.
The elevation of AICRIP to directorate status in 1975 added an additional mandate to conduct strategic and applied research in the major thrust areas of irrigated rice, which marked the beginning of the second phase, in which facilities were strengthened, new research networks initiated, and transfer of technology and breeder seed production activities undertaken. This impressive growth culminated in the largest network with 46 funded centers and more than 100 voluntary cooperating centers. The intellectual input of more than 300 multidisciplinary teams of scientists associated with AICRIP is its greatest strength.
During 2011-13, the magnitude of trials conducted at various experimental sites ranged from 2,049 (2012) to 2,324 (2011) from all the disciplines included in AICRIP activity, which include breeding, hybrid rice, agronomy, physiology, soil science, entomology, and pathology (Table 1). Reviewing only the breeding and varietal trials during the last three years, the total number of trials organized was 117, constituted by 2,878 nominations contributed by rice breeders from both public and private sector organizations from all over India, who are partners in this endeavor. The program is so extensive, with the total number of experimental test sites being 2,380 covering all ecosystems such as irrigated, rainfed uplands, shallow lowlands, semi-deep and deepwater areas, boro, problem soil situations, and hill regions, and is one of the biggest cooperative partnerships in India. As rice in India is grown on nearly 44 million hectares (the highest amount of area in the world), AICRIP has been through its massive targeted efforts attempting to find solutions to problems on hand with the emerging newer issues.
Smaller networks exclusively devoted to the development and use of hybrid rice technology, rice biotechnology, improvement of quality rice for export, and evaluation of rice germplasm for biotic stresses and others have achieved impressive results in the realms of varietal and crop management advisories. The mission of DRR as outlined in vision 2025 is to develop technologies to enhance rice productivity, resource- and input-use efficiency, and profitability of rice cultivation without adversely affecting the environment. The mandate of DRR involves:
- Coordinating multilocation testing at the national level to identify appropriate varietal and management technologies for all rice ecosystems.
- Conducting strategic and applied research in the major thrust areas of irrigated rice aimed at enhancing production, productivity, and profitability and at preserving environmental quality.
- Initiating and coordinating research networks relating to problems of national and regional importance.
- Serving as a major center for the exchange of research material and information.
- Accelerating the pace of technology transfer through frontline demonstrations, training programs, and ICT.
- Developing linkages with national, international, and private organizations for collaborative research programs.
- Providing consultancy services and undertaking contractual research.
For this purpose, the AICRIP multi-tier/multi-location testing program with the objective of developing suitable varieties and crop management advisories for diverse conditions was instrumental in developing and releasing 1,011 varieties, including 67 hybrids, up to 2012-13. Of these varieties, 623 (constituting 61.6%) are for irrigated areas while 380 (35.5%) are for rainfed ecosystems. Again, the Central Variety Release Committee approved the release of 147 varieties/hybrids (14.5%) for wider adaptability while 26 State Variety Release Committees released 856 (84.7%) varieties/hybrids. Among these varietal releases, 125 are for rainfed uplands, 186 for rainfed shallow lowlands, 40 for semideep and 17 for deepwater conditions, 42 for irrigated areas, 8 for upland hills, 41 for saline and alkaline areas, 19 for boro season, 67 basmati and aromatic short-grain varieties, and 4 for aerobic conditions (Fig. 2 and Table 2).
Emphasis was given to developing varieties with resistance to biotic stresses for endemic areas, as in some years crop losses caused by bacterial leaf blight (BLB) and rice tungro virus (RTV) among diseases and brown planthopper (BPH) and gall midge among insect pests were devastating in different parts of the country. Systematic breeding efforts of the last five decades resulted in the development and release of a wide choice of varieties with specific and multiple resistance. These include varieties predominantly resistant to blast followed by BLB, RTV, stem borer, green leafhopper, BPH, white-backed planthopper, and gall midge. These varieties have greatly accelerated rice production and productivity in the country. The spread of HYVs doubled from a meager 37.9% in 1966-67 to nearly 84% by 2010. Likewise, the demand for breeder seed shot up from about 250 tons in the mid-1990s to 5,552 tons by 2013-14, indicating the special efforts made by the government through the National Seed Project (NSP) to enhance the availability of pure seed of new varieties as it is vital that the gains of varietal technology reach farmers in the shortest possible time.
Varieties such as Swarna, Samba Mahsuri (BPT 5204), Cottondora Sannalu (MTU 1010), Vijetha (MTU 1001), Jyothi, Sarjoo 52, IR64, Jaya, IR36, and NDR 359 need a special mention since they have wide coverage across several states and are termed “mega-varieties” and many of them are also the recipient parents for the introgression of biotic and abiotic stress tolerance genes through molecular marker-aided selection (MAS). Some of the landmark MAS-derived products are Swarna-Sub1, exhibiting 12 days of submergence tolerance 4 weeks after planting, with the major SUB1 QTL introgressed from traditional flood-resistant Indian variety FR13A, and Improved Samba Mahsuri and Improved Pusa Basmati 1 introgressed with multiple BLB-resistance genes showing a high degree of resistance to BLB but similar to recurrent parents in all traits that are known for their excellent grain quality in nonbasmati and basmati segments, respectively.
Some of the popular hybrids that are widely grown are PHB 71, KRH 2, PA 6444, PA 6201, DRRH 2, Pusa RH10, and Sahyadri. Having realized the scope and potential of quality rice for export, special thrust was given to the genetic enhancement of quality rice in the country, which led to the release of 67 basmati and other aromatic varieties. Thus, a wide varietal choice of high-yielding basmati varieties is available, which raised the quantum of exports of basmati rice from the country. Becoming the top rice exporter in the world recently (in 2012), India earned US$564 million in 2012-13. Being a niche exporter for basmati rice, India exported about 3.4 million tons earning US$323 million. Some of the notable export-quality basmati varieties are Taroari Basmati, Basmati 386, and Basmati CSR 30 among the tall types, with the latter variety also having tolerance of sodicity, and Pusa Basmati 1121, Pusa Basmati 1, Pusa 1509, Vasumati, Punjab Mehak 1, Vallabh Bsmati, etc., among the evolved highly productive basmati varieties released recently.
Likewise, in the rainfed rice ecosystem, no visible progress could be discerned for a long time. Augmented national effort together with the active participation of the IRRI-sponsored upland and lowland consortia resulted in the development and release of many promising strains. Tapping the yield potential of these varieties and their spread would bring the much-needed advancement in production to this vast long-neglected region. Savithri, Bahadur, Sona Mahsuri, Samba Mahsuri, Improved Samba Mahsuri, Swarna, Krishna Veni, Kranti, Kanak, Swarnadhan, Shashi, and ADT 44 for rainfed shallow lowlands; Amulya, Utkal Prabha, Sabita, Jitendra, and Purnendu for semideep water; Jalmagna, Barah Avarodhi, Dinesh, Eremaphou, and Sunil for deepwater areas; and Tulasi, Varalu, PNR 381, Vandana, Kalinga III, Danteswari, Vana Prabha, Neela, and Narendradhan 97 for rainfed uplands are important varieties released for the rainfed ecosystem.