Rice, the second most widely grown cereal crop after wheat, gifted with rich genetic repositoire, is the staple food for more than half of the global human population. More than one hundred thousand landraces and improved cultivar collections available in the rice germplasm world over largely contribute to the rich genetic diversity of rice. Driven by natural selection of varieties distributed in diverse agro-ecoclimatic conditions coupled with continuous selection by man for his diverse in quality and aesthetic preferences, a unique rice varietal group has emerged, which has come to be known as "Basmati Rice", a specialty rice all over the world.
Regarded as the "king of the rices", Basmati rice occupies a special place among all aromatic rice cultivars by virtue of its unique traits characterized by extra long slender grain, excessive elongation on cooking, soft and fluffy texture of the cooked rice, and pleasant distinct aroma. As a result, it commands premium price in the domestic as well as overseas markets (Archak et al 2007; Nagaraju et al 2002; Vemireddy et al 2007). Among several grown and marketed Basmati varieties, only six in India are recognized as traditional Basmati (TB) varieties of which, Basmati370, Taraori Basmati and Dehradun Basmati are the most popular ones (Archak et al 2007). Unlike other aromatic rices, Basmati rice expresses its unique quality traits only when grown in the north-western foot hills of the Himalayan region in the Indian sub-continent. And, because of its location and associated specific quality performance Basmati is now a Geographical Indication (GI) belonging to a specific geographical area in the Indian subcontinent and it is like "champagne" among wines and "scotch" among whisky brands. Basmati rice has attained "heritage rice" status as if is considered "farmers cultivar" grown by farmers in India and Pakistan for more than 250 years covering the Punjab region of India and Pakistan and sub-Himalayan regions of Haryana and Uttar Pradesh of India (Figure 1). The special qualities of Basmati are attributed to unique and complex combinations of soil, water, climate and cultural practices under which it is grown besides inherent genetics governing these features. Thus attempts to replicate the unique Basmati grain qualities by growing Basmati rice anywhere else in the world have not been successful.
Fig. 1 Basmati rice growing areas of India and Pakistan
History of Basmati rice
Reference to existence of some aromatic rices can be traced to the documents of Susrutha (circa 400 BC), a great Indian pioneer in medicine and surgery. The first usage of the word "basmati" can be found in Punjabi classic Heer Ranjah (1766) by the Punjabi poet Waris Shah . The usage of names of rice cultivars such as Basmati, Begumi, Satthi (60-day rice) suggests that "Basmati" rices have been in cultivation since 1700 AD. Subsequent reference to the "Basmati" can be found in the book "A dictionary of the Economic Products of India" compiled by George Watt and published in 1891. The word "Basmati" appears to have been derived from two Sanskrit words i.e, vaas (fragrance) and matup (possessing). Vaasmati pronounced now as Basmati appears to mean the one that "possesses fragrance". In North India "va" is often pronounced as "ba", and that is how the word "vasmati" must have become "Basmati". Basmati rice was a preferred rice for the preparations of Biryani and Pulao on special occasions and was patronized by emperors. Poets have composed poems admiring the special qualities of Basmati rice. The credit for conserving and improving Basmati rices to suit the socioeconomic and agro-climatic should go to farmers of the geographical region in the Indian subcontinent. The names of Basmati varieties that exist now are quite often suggestive of the places where they are grown. For instance, Taraori Basmati is from the Taraori region in Haryana and Dehraduni Basmati from Dehradun in Uttaranchal.
Diversity in Basmati rice
As mentioned earlier, rice is quite rich in its genetic diversity distributed worldwide. Out of 21 valid species of genus Oryza, only two viz., Oryza sativa (Asian cultivar) and Oryza glaberrima (African cultivar) are cultivated (Vaughan et al 2003). Since its origin and domestication, O. sativa is reported to have undergone differentiation into three eco-geographical races or sub-species, viz., indica, japonica (temperate) and javanica (tropical japonica) (Singh et al 2000; Vaughan et al 2003). The diversification of O. sativa is not confined only to these three sub species as it continued to further differentiate into different varieties as a result of natural and human selections over centuries under diverse agro-climates, cultural practices etc. According to traditional classification, Basmati is described under indica group because of its long and thin grains (Sweeney and McCouch 2007). However, earlier reports on diversity studies have suggested that Basmati varieties form a distinct group of their own separated from indica and japonica. For instance, isozyme analysis of Glaszmann, reveals Asian cultivars to have differentiated into six varietal groups viz., indica, aus, ashinas, rayadas, aromatic, and japonica.
Majority of the aromatic rice varieties that included Basmati were clustered in a separate group (Group V), whereas typical indica and japonica varieties formed Group I and Group IV respectively. Many of the varieties belonging to the Group V are characterized by elongated kernels after cooking. Although aromatic varieties separated quite well from the other groups, they were comparatively more closer to the japonica group than to indica group (Garris et al 2005). Findings from a recent study, using 169 microsatellite loci and two chloroplast loci, are in complete agreement with the results of Glaszmann (Garris et al 2005). High percentage of hybrid sterility of crosses of Basmati with typical indica varieties further confirm that Basmati group is more distant genetically from indica (Nagaraju et al 2002). Recent report based on the genetic analysis of betaine aldehyde dehydrogenase gene (BADH2) underlying the fragrance trait suggests that basmati rice is evolutionarly closely related to Japonica gene pool. (Kavach et al 2009).
Nagaraju et al (2002) studied genetic relationship of traditional basmati (TB), evolved basmati (EB), and non-basmati varieties using simple sequence repeats (SSR) loci and fluorescent labelled inter-SSR-PCR (FISSR) primers. The findings reported in the study indicate that in likelihood all the traditional basmati varieties might have evolved from a single landrace and whatever little genetic variation observed among them could be as a result of selection practiced over years by farmers keeping in view the consumer practices as well as their own needs. Almost all the TB varieties known by different names are selections from one local variety, in all probability, Basmati 370. Isozyme patterns of 60 of the 65 Pakistani Basmati accessions and nine Indian Basmati varieties with the exception of Karnal Local matched that of Basmati 370 and Dehraduni Basmati (Nagaraju et al 2002). These results further support the view that all known TB varieties of India and Pakistan might have been the derivatives of either Basmati370-like or Dehraduni Basmati-like varieties.
Archak S, Nagaraju J (2007) Computational prediction of rice (Oryza sativa) miRNA targets. Genomics, Proteomics and Bioinformatics 5: 196-206. PDF
Lakshminarayanareddy V, Archak S, Nagaraju J (2007) Capillary
electrophoresis is essential for microsatellite marker based detection
and quantification of adulteration of Basmati rice (Oryza sativa).
Journal of Agriculture and Food Chemistry 55: 8112-8117. PDF
- Nagaraju J*, Kathirvel M, Kumar RR, Siddiq EA, Hasnain SE (2002) Genetic analysis of traditional and evolved Basmati and non-Basmati rice varieties by using fluorescence-based ISSR-PCR and SSR markers. Proceedings of the National Academy of Sciences USA 99: 5836-5841. PDF
* Corresponding author
Garris AJ, Tai TH, Coburn J, Kresovich S and McCouch S (2005) Genetic structure and diversity in Oryza sativa L. Genetics 169: 1631‐1638.
Vaughan DA, Morishima H, Kadowaki K (2003) Diversity in the Oryza genus: current Opinion in Pl. Biology 6: 139-146