Development of the PARMS Markers of the Waxy Gene and Utilization in Discriminating Wild Accessions, and Cultivated Rice (Oryza sativa L.) with Different Eating and Cooking Quality

Abstract

Amylose content (AC) is the major indicator of rice eating and cooking quality (ECQ). Its synthesis in rice endosperm is mainly regulated by the protein, granule-bound starch synthase 1, which is encoded by the waxy gene (Os06g0133000, LOC_Os06g04200). The diversity of AC is largely attributable to the allelic variation at the Wx locus and the development of effective and accurate functional molecular markers to target rice variant alleles is crucial in the breeding strategy. In the present study, we developed six pairs of penta-primer amplification refractory mutation system (PARMS) markers to distinguish between Wxlv, Wxa, Wxin, Wxb, Wxmp, and Wxop,hp. These markers were successfully used to screen the genotype of large assets of genetic resources including 98 wild accessions, 55 cultivars, and 22 parental lines. Our results showed that Wxb in a low AC type was predominant in Guangxi cultivated rice as a result of cultural preference, while Wxlv in the wild accessions. Moreover, our findings surprisingly revealed the presence of Wxb in wild accession, which is a new outcome that may contribute to understanding the origin, selection and domestication processes of rice. These functional markers could be effectively used in marker-assisted breeding to improve selection efficiency of cultivars with desired AC in the early generation.

Impacts of Inherent Components and Nitrogen Fertilizer on Eating and Cooking Quality of Rice: A Review

“…The Wx gene is the major decisive factor of AC and performs a determining role in rice ECQ [ 26 ]. So far, a series of Wx alleles have been reported, such as Wx , Wx lv , Wx in , Wx a , Wx b , Wx mw/la , Wx op/hp , Wx mp , and Wx mq [ 94 , 95 , 96 , 97 , 98 ]. In normal rice varieties, high AC level (>25%) are decided by the Wx lv and Wx a alleles; nevertheless, the Wx lv allele was recognized as the ancestor type of the Wx gene, conducing to a higher AC level than that of the Wx a allele [ 99 ].…”

Grain Quality Evaluation of Several Upland Rice Varieties in Indonesia

“…According to Table 7, the types of Inpago 8, Inpago 10, and Rindang 1 are in the medium amylose group (20-25%), while Inpago 12, Inpago Unsoed, and Rindang 2 are in the low amylose group (10-20%). [12,26] claim that from a breeder's perspective, the amylose content is crucial because it significantly affects customer choice. When rice is cooked, it is mushy and sticky if the amylose content is low; nevertheless,when the amylose content rises, the rice gets tougher [18,27].…”