Characterization of On-farm Rice Germplasm in an Area of the Crop’s Center of Diversity

Abstract

The seed of rice (Oryza sativa L.) from the highlands of northern Thailand, which is located within the species' centre of diversity, constitutes some of the world's last local rice germplasm still retained on-farm, provides local farmers and communities with a readily accessible resource, and is a source of value-adding traits for rice breeding. This paper reports on the germplasm represented by 281 seed samples collected in 2013 from an area of the highlands between latitudes 17.76°N to 20.18°N and longitudes 97.76°E to 100.48°E. The samples were provided by farmers belonging to 10 ethnicities, in number that closely correlated with the groups' share of the highland population (r = 0.84; P < 0.01). Compared with the slender grain rice of the lowlands, the highland germplasm was distinctive in its grain shape, and classed as large grain type in the husk, and medium grain type as de-husked, brown rice. The rice, which was predominantly of non-glutinous grain type and grown mainly as upland rice, had generally higher iron concentrations than rice in the lowlands; thus demonstrating how an on-farm rice germplasm may directly benefit local farmers and communities who consume the rice they grow. In addition, potential value-adding traits were identified in varieties and seed samples with the highest zinc density and novel rice with pigmented pericarp and high anti-oxidative capacity.

The Potential of High-Anthocyanin Purple Rice as a Functional Ingredient in Human Health

“…In Northeastern Thailand, the total anthocyanin concentration of 30 local glutinous purple rice accessions ranged from 26 to 254 mg/100 g [54]. The latter study also evaluated total anthocyanin concentration among Anthocyanin occurrence in the grain is very divergent, since most purple rice varieties are traditional/local rice that reflect differences among regions and growing environments (glutinous and non-glutinous rice types and upland and lowland rice types) [51,52]. Likewise, the majority of the genetic variation being within regions rather than between regions was reported in the traditional Philippine pigmented rice, and 589 pigmented rice accessions occur as both indica and japonica types [53].…”

Variation in nutritional quality of pigmented rice varieties under different water regimes

“…It is used in traditional ceremonies for preparation of deserts and special foods with believing that it contains medicinal properties such as stop bleeding after childbirth, bringing down fever to curing skin disease and diarrhea (Kaladee, 2011). Recently, it has been identified that the local pigmented rice varieties contain high nutritional qualities which are valuable for farmers and consumers such as Fe, Zn, anthocyanin and antioxidant capacity (Jaksomsak et al, 2015;Jamjod et al, 2017;Pintasen et al, 2007). These are the resources of potential value-adding traits for rice breeder and market benefits as special-quality rice.…”

Identifying rice grains with premium nutritional quality among on-farm germplasm in the highlands of Northern Thailand

“…Boonsit et al, 2010;Panomjan et al, 2016) as well as to directly benefit those who consume the rice they grow and they also provide a source of genetic traits in breeding programmes. On the other hand, commercialisation of rice production, especially in the countries such as Thailand, Vietnam, China and India where a great amount of the production is consumed and exported annually, has led to the replacement of local rice varieties by only a few mega-varieties; however, local rice varieties are still grown by farmers in a few areas, including the highlands of Laos (Xiongsiyee et al, 2018) and Northern Thailand (Jamjod et al, 2017), which are part of the centre of diversity for Oryza sativa (Harlan, 1992). Thus, identifying nutritional quality traits among the local rice varieties is not only beneficial to health-conscious consumers, but would also allow the further in-depth physiological study and breeding programme.…”