For this post I’m delighted to introduce an article provided by guest contributor Saikat Basu. Saikat is an Indian scientist currently working in Canada. This paper, which was co-written by P Zandi from the Institute of Crop Science in Beijing, is a great example of international collaboration on an issue with global implications.
As Saikat reports , “almost half of the world’s communities in developing and under developed nations are suffering from micronutrient malnutrition”. The need for viable new crop solutions is of critical importance. Green Super Rice seems to offer a potential solution.
Climate change is an out of reach global crisis that has notable negative impact on smallholder farmers with limited land and financial resources. Abrupt changes in weather conditions can cause irreparable damage to their final harvest, which makes them more vulnerable. Releasing GSR varieties with multiple stress-resistant features can relieve farmer’s pains and assist them in creating a more successful livelihood.
GSR varieties are composed of almost 500 promising rice varieties and hybrids with the capability to withstand abiotic stresses including salinity, floods and drought, which are particularly more deleterious. They have proven to be more resistant despite receiving less inputs, such as pesticides and chemical fertilizers, that have an adverse impact on human beings and the environment.
Objectives of the Green Super Rice Project
The GSR project, which at first was funded by the Chinese Government and the Bill & Melinda Gates Foundation, has pursuing the following goals:
- Development of the second generation of GSR inbred and hybrid rice varieties for rice growing countries in Africa and Asia through implementing a shuttle breeding (or molecular marker assisted breeding) approach;
- Resequencing 3,000 rice accessions belonging to the core collection of rice germplasm and parental lines in the GSR breeding programs and making and extending a global genotyping platform for rice molecular breeding programs;
- Examining and releasing FRESHLY developed PROMISING GSR varieties in the considered African and Asian nations;
- Development of highly efficient and the most updated approaches in seed production technology and distribution of developed GSR rice varieties in the considered African and Asian nations;
- Adoption and development of appropriate crop management technologies with national agricultural research and extension systems for newly developed GSR varieties in diverse target environments;
- Building a reasonable trajectory in target African-Asian countries from the perspective of GSR breeding technology and seed production;
- Testing project effect; and
- Efficient management of the GSR project.
Rice Farmers face many challenges
Rice is the main staple food for more than one fourth of the world population. In the last 50 years ago, rice yield performance has encountered two big leaps. Increasing harvest index through reducing plant height, utilization of semi dwarf genes or even making use of heterosis phenomena by producing hybrid rice could possibly increase rice yield (genetic improvement). Moreover, rapid population growth and economic development tend to increased food production. During the last decades several major national and international attempts have been made to break the present yield ceiling in rice through developing super rice or super hybrid rice.
In north part of Iran farmers usually suffer from permanent climatic disasters, such as water shortage, low rainfall during cropping season, heat stress or even flooding.
The GSR project is very useful for the rice growing regions as to help farmers grow rice with peace of mind. Before writing over the main challenges ahead of the GSR project we should repeatedly emphasis that local farmers usually disregard to accept new techniques because they have to be sure that their final harvest will be sold with ease.
Fig. 1: Rice field showing temporal climate changing effect (drought stress) on Hashemi rice variety in north part of Iran (Guilan Province, Fouman County, rural zone).
In Iran (particularly in Guilan province) farmers have their own policy and do not easily change the local rice varieties like ‘Hashemi’ or ‘Ali Kazemi’ with newly introduced or promising varieties irrespective of possessing superior features. Dr Johar Ali, a senior researcher in the field of Green super rice project, has been working in Rasht Research Institute for more than 5 years. He came to Iran as to introducing hybrid rice technology and replacing it with traditional varieties. Later late Dr Dorosti has also been working with Dr Johar Ali. His contribution to this project was undeniable as he introduced new Hybrid Rice variety known as Bahar 1. Unfortunately, after all efforts made by Dr Johar Ali the Hybrid rice project, regardless of some regional progress, could not be proceeded any further and remained inchoate. Anyhow, as in any new project there must be a number of challenges to achieve the goal of increasing rice production following a sustainable trajectory (Yorbe et al., 2014):
- The vast majority of insects (stemborers, leaffolders, brown plant hoppers, Nilapar-vata lugens) and diseases (blast, bacterial blight, sheath blight) in most rice-growing areas. For a long period, insect/disease control was deeply contingent upon indiscriminate applications of chemical pesticides. Intensive use of chemicals has been found to be less effective since it poses producers and consumers to severe health crises, eradicate natural enemies and creates serious environmental pollutions.
- Over application of fertilizers application. This challenge has been started since 40 years ago and triggered several main (lodging, pest damage, yield loss, poor eating and cooking quality) side effects, such as reduction in economic return and placing an unbearable burden on the farmers and out of range enrichment of water with nutrients in the environment. Therefore, relying on crops that are less dependent on excess application of fertilizers is a turning point in sustainable agriculture.
- Water shortage is a global crisis. Drought stress is the most important limiting factor in rice producing regions. Insufficient rainfall, uneven dissemination of rainfall and variation in rainfall patterns are known as the main factors in inducing stress.
- The productivity level in marginal lands where rice is mostly cultivated in is low due to combination of several constrains including drought, soil’s poor fertility and some other adverse environmental conditions.
Historically, many breeding programs built on the basis of rice grain quality. Primitive rice high- yielding cultivars and hybrids had relatively poor quality. Concurrent to the increased living criteria, a serious attention has been made towards cooking, consumption and appearance of rice grains.
A new, viable source of micronutrients is urgently needed
Almost half of the world’s communities in developing and under developed nations are suffering from micronutrient malnutrition. Therefore, rice production should enhance in two dimensions of quality and quantity while being fully in coordination with its environmental growth (sustainable yield) conditions. Ensuring a sustainable production requires a stepwise reduction in application of agricultural inputs, such as fertilizers, pesticides and irrigation. The main goal of Green Super Rice (GSR) is to increase both yield and quality consecutively while reducing rudimentary inputs.
To sum up, GSR should subtend at least five exclusivities: being adequately resistant to major diseases and/or insects, being highly efficient in nutrient absorption, transmission and utilization, being resistant to abiotic stresses namely drought stress, having favorable quality and high stability, and possessing advance yield potential (Fig. 2).
As seen in Fig. 2, development of GSR project is highly contingent on compilation of various strategies to be formulated through amalgamating genomic resources, germplasms, molecular technology and breeding with target traits (i.e. N- and P-nutrient efficiency, quality, yield, insect and disease resistances, drought resistance etc.) (Zhan, 2007).
For identification of genes/ germplasms with close association to the earlier defined traits one needs to highlight for the approaches (Yorbe et al., 2014) as mentioned below:
- Screening of germplasm collections;
- Mapping and identification of genes;
- Screening of mutant libraries;
- Microarray analysis of differentially regulated genes;
- Functional test of candidate genes by transgenic analysis
It should be pointed that any tangible progresses in identifying the corresponding genes and further advancement of the GSR technology (Fig. 3) must have the following parameters under consideration (Yorbe et al., 2014):
- Resistance to Stemborers and Leaffolders
- Resistance to BPH
- Identification of Genes for Disease Resistance and Development of Disease-Resistant Rice
- Identification of Genes for Nutrient-Use Efficiency: Identifying genes for N-use/ P-use efficiency
- Identification of Genes for Drought Resistance and Development of Drought-Resistant Rice
- Identification of Genes for Quality Improvement
- Identification of Genes for Yield Traits
Then, the identified genes would incorporate into breeding lines through MAS and/or transformation approach. Eventually, accumulation of desired genes would lead to further improvement of rice cultivars (GSR technology).