Commercial Cultivation of Australian Wild Oryza spp.: A Review and Conceptual Framework for Future Research Needs

Wild Oryza species are being targeted for commercial cultivation due to their high nutritional grain profile, and their association with Aboriginal people in many regions. Australian wild Oryza species have potential as high-value, low-volume, culturally identified, and nutritious food, especially in gourmet food, tourism, restaurants, and value-added products. However, the basic agronomic protocols for their cultivation as a field crop are unknown. In this review, we identify the major factors supporting the commercial production of wild Oryza, including their stress-tolerant capacity, excellent grain quality attributes, and Indigenous cultural identification of their grains. The key challenges to be faced during the development of a wild rice industry are also discussed which include management barriers, processing issues, undesirable wild traits, and environmental concern. This manuscript proposes the use of agronomic research, in combination with breeding programs, as an overarching framework for the conceptualization and implementation of a successful wild rice industry, using the North American wild rice industry as a case study. The framework also suggests an integrated system that connects producers, industry, and government stakeholders. The suggested procedures for developing a wild rice industry in Australia are also applicable for other wild Oryza species.

Substitution mapping of the major quantitative trait loci controlling stigma exsertion rate from Oryza glumaepatula

Background: Stigma exsertion rate (SER) is a key determinant for the outcrossing ability of male sterility lines (MSLs) in hybrid rice seed production. In the process of domestication, the outcrossing ability of cultivated rice varieties decreased, while that of wild Oryza species kept strong. Here, we detected the quantitative trait loci (QTLs) controlling SER using a set of single-segment substitution lines (SSSLs) derived from O. glumaepatula , a wild Oryza species. Results: Seven QTLs for SER were located on 5 chromosomes. qSER-1a and qSER-1b were located on chromosome 1. qSER-3a and qSER-3b were mapped on chromosome 3, and qSER-3b was further located at an estimated interval of 898.8kb by secondary substitution mapping. qSER-5 , qSER-9 and qSER-10 were identified on chromosomes 5, 9 and 10, respectively, and qSER-9 was delimited to an estimated region of 551.9kb by secondary substitution mapping. The additive effects of the 7 QTLs ranged from 10.6% to 14.8%, which were higher than those of most loci for SER reported previously. Conclusions: qSER-1a and qSER-1b are novel loci for SER on chromosome 1. All of the 7 QTLs have major effects on SER. The major QTLs of SER will help to develop MSLs with strong outcrossing ability.

The Possibility of Gene Flow Between Cultivated and Wild Rice in Ghana, A Review

Several transgenic rice lines have been developed and are currently under field trials around the world. There are future plans for the commercial release of transgenic rice into the environment. Rice is an autogamous plant and therefore not perceived to be a very high candidate for pollen mediated gene flow to wild and weedy relatives. However, in a tropical environment like Ghana, where sexually compatible wild Oryza species which belongs to the AA genome are present within the ecology of cultivated rice, the possibility of gene flow to wild species cannot be overlooked. There is little evidence on gene flow and its consequences on the wild rice species should they acquire useful genes through gene flow. This review discusses the chances of cultivated to wild rice gene flow in Ghana and the biosafety considerations that should be put in place before the commercial release of genetically modified (GM) rice.