Rice is the major cereal crop in Asia where 90% of the world’s rice is produced and consumed. Rice production and productivity need to keep pace with a growing global population likely to reach 9 billion by 2050 in order to have a hunger-free world and to ensure sustainable production in the face of depleting resources such as land, water and nutrients as well as changing climatic conditions.

1. Presented by
Dhanuja N
2019508005
I M.Sc., GPB
BREEDING RICE FOR
SUSTAINABLE AGRICULTURE

2. SUSTAINABLE AGRICULTURE
 Sustainable agriculture is farming in sustainable
ways, which means meeting society's present food
and textile needs, without compromising the ability for
current or future generations to meet their needs.
 Agriculture has an enormous environmental footprint,
playing an outsized role in causing climate
change, water scarcity, land
degradation, deforestation and other processes. it is
simultaneously causing environmental changes and
being impacted by these changes
 Sustainable agriculture provides a potential solution to
enable agricultural systems to feed a growing
population within the changing environmental
conditions.

3. DIFFERENT VIEW POINTS
 There is debate on the definition of sustainability regarding
agriculture. The definition could be characterized by two
different approaches: an ecocentric approach and a
technocentric approach.
 The ecocentric approach emphasizes no- or low-growth
levels of human development, and focuses
on organic and biodynamic farming techniques with the
goal of changing consumption patterns, and resource
allocation and usage.
 The technocentric approach argues that sustainability can
be attained through a variety of strategies, from the view
that state-led modification of the industrial system like
conservation-oriented farming systems should be
implemented, to the argument that biotechnology is the
best way to meet the increasing demand for food.

4. RICE
 Rice is the major cereal crop in Asia where 90% of the
world’s rice is produced and consumed. As a C3 crop,
rice productivity has reached a very high level of up to
>8 t/ha in the irrigated areas of many countries,
resulting primarily from improvement in breeding in
previous decades, including the ‘Green Revolution’
since 1950s and the development of hybrid rice
technology in China since late 1970s.
 Rice production and productivity need to keep pace
with a growing global population likely to reach 9
billion by 2050 in order to have a hunger-free world
and to ensure sustainable production in the face of
depleting resources such as land, water and nutrients
as well as changing climatic conditions.

5. RICE
 It’s important to mention that rice farming produces 10% of
global methane emissions and requires 34-43% of the
world’s irrigation water. In order to decrease water use, soil
pollution, and methane emissions, as well as improve their
yields, farmers need to embrace sustainable farm
practices.
 Irrigated rice production requires large amounts of water,
with 1 kg of rice grain requiring 2500 L of water
 Current water intensive rice cultivation practices may
decrease grain concentrations of essential micronutrients
(e.g., zinc, copper, selenium, iron, and manganese), and
elevate levels of the potentially toxic trace elements such
as arsenic (a class one, nonthreshold human carcinogen)
in rice.

6. CHALLENGES
From a breeder’s point of view, there are a number of
challenges to achieve sustainable rice production.
Some are
 Low input rice
 Organic rice
 Nutritive rice
 Climate smart rice
 Pest and disease resistant rice

7. LOW INPUT RICE
 Modern high performance varieties are usually bred
for high input systems
 However, as resources decline and populations grow,
high-input systems become less sustainable and
realistic.
 Plant breeding programs focused on developing
genotypes adapted to specific agricultural
environments and lower inputs could help attain
sustainable, higher productions with lower energy
costs to accommodate the growing population

9.  Modern crop improvement programs generally select
under optimal conditions, therefore the focus is on
genotypic selection based on increased yield
performance or fruit/grain weight. This method of
artificial selection results with a predictably uniform
crop, in which genetic variability is restricted
 However, many of the food production systems
around the world are either low-input or under stress
conditions and cannot depend on the purchase of
supplies.

10. Yield comparison of commercial and
local varieties produced under high and
low-input conditions

11.  Breeding programs thus need to be developed that
examine potential varieties more suited to low-yielding
conditions, in which varieties would be selected that
have more advantageous adaptations in stress
conditions such as
 delayed leaf senescence,
 improved nutrient economy,
 local environmental fitness,
 consistent yield, and
 pest/disease resistance, thus increasing the
profitability of sustainable low-input systems.

13. ORGANIC RICE
 Organic farmers need specific varieties that are adapted to
their lower input farming system and can perform higher
yield stability than conventional varieties varieties having
traits amenable for organic farming (organic varieties) are
the missing link in the organic production chain.
 Broadening the genetic basis becomes important when we
want to search for adaptation to organic farming.
 Two land races namely, ‘Kuthiru’ and ‘Orkayama’ for a
broader genetic basis as a source for adaptation ability
and are adapted to a unique organic saline prone
ecosystem of Kerala
 Two other parents included in the breeding programme
were the varieties, ‘Jaya’ and ‘Mahsuri’ which are usually
cultivated by farmers under low input conditions.

14. Culture MK 157 is
the first organic
wetland rice cultivar
suitable for both
organic farming and
conventional
farming, developed
through the
combined plant
breeding strategies
of pedigree
breeding, organic
plant breeding and
participatory plant
breeding.

15. NUTRITIVE RICE
 Food security goes beyond hunger – it stretches to
include regular access to safe, nutritious, and
affordable food.
 While the number of people suffering from hunger
globally is rising above 820 million, an additional 1.3
billion people are affected by moderate levels of
nutrition insecurity because they have inadequate
access to safe and nutritious food.
 Developing biofortified rice varieties with enriched
micronutrient content such as provitamin A, iron, and
zinc, as well as identifying rice varieties with lower
glycemic index and antioxidant properties.

16. BIOFORTIFICATION
 Biofortification is the process of improving the nutritional
quality of food crops. This can be achieved through
agronomic practices, conventional breeding or more
advanced biotechnology tools such as genetic engineering
and genome editing.
 scientists to screen for nutrition-enhancing traits in rice,
and identify the most appropriate biofortification method to
improve these traits.
 Biofortified rice varieties in the early stages of research
include:
 Stacked beta-carotene, iron and zinc lines
 Gene-edited high zinc rice
 High Folate rice
 High Lysine rice
 High Leucine rice
 Non-GM High iron rice

17. GOLDEN RICE
 Golden rice is a variety of rice (Oryza sativa) produced
through genetic engineering to biosynthesize beta-
carotene, a precursor of vitamin A, in the edible parts of
rice
 In several countries, golden rice has been bred with local
rice cultivars
 Golden rice was created by transforming rice with two
beta-carotene biosynthesis genes:
 psy (phytoene synthase) from daffodil ('Narcissus
pseudonarcissus')
 crtI (phytoene desaturase) from the soil
bacterium Erwinia uredovora
 Golden rice 2 produces 23 times more carotenoids than
golden rice (up to 37 µg/g), and preferentially accumulates

19. CLIMATE SMART RICE
 Rice production is both a victim and a contributor to
climate change.
 Drought, flood, saltwater, and extreme temperatures
devastate crops and risk the livelihoods of 144 million
smallholder rice farmers each growing season.
 At the same time, traditional cultivation methods, such as
flooding paddy fields and burning rice straw in open fields,
contribute approximately 10% of global man-made
methane, a potent greenhouse gas.
 It is important to develop and adapt climate-responsive
varieties.
 This includes drought, flood, heat, cold, and soil problems
like high salt and iron toxicity.

20.  Breeders use a breeding method known as marker-
assisted breeding. It helps breeders incorporate
specific desirable traits into new varieties with more
accuracy and speed.
 Drought tolerant varieties by IRRI Sahbhagi Dhan in
India, the Sahod Ulan in the Philippines, and
the Sookha (Sukkha) Dhan varieties in Nepal.
 IRRI is working towards introducing drought tolerance
into popular high-yielding rice varieties including IR64,
Swarna, and Vandna.

21. FLOOD-TOLERANT RICE
 Floods can affect rice crops at any stage of growth. These
could be short-term flash floods or long-term stagnant
flooding
 Plant breeders have discovered that a single gene, the
SUB1 gene, confers resistance to submergence of up to
14 days.
 Scientists were able to isolate the SUB1A gene, derived
from an Indian rice variety, and identify the genetic control
of submergence tolerance. The SUB1A gene activates
when the plant is submerged, making it dormant and
conserves its energy until the flood water recedes. This
allows the plant to successfully recover after the flooding.
 Flood-tolerant varieties that have been released and are
now being planted include Swarna Sub1 in India, Samba
Mahsuri in Bangladesh, IR64-Sub1 in the Philippines, and

24. SALT-TOLERANT RICE
 Millions of hectares of land suited to rice production in Asia
and Africa are currently not used because of high salt
content. Rising sea levels brings salt water further inland,
contributing to soil salinity.
 scientists have identified a major region of the rice genome
called Saltol that gives the rice plant tolerance to salinity.
Saltol is being used to help develop varieties that can cope
with exposure to salt during the seedling and reproductive
stages of the plant.
 BRRI Dhan 11, 28, 29 varieties released in Bangladesh
 Recent work at IRRI has shown that the SUB1 gene and
Saltol can be combined in the same type of rice,
increasing the rice plant's tolerance to salinity and
submergence.

25. Heat-tolerant rice
 Rice plants are most sensitive at the flowering and
ripening stages. Both yield and grain quality are
adversely affected.
 scientists are looking for rice that can tolerate high
temperatures by screening improved and traditional
rice varieties.
 Another mechanism for rice heat tolerance is early-
morning flowering, which escapes the high
temperature at midday. It was found that O.
glaberrima, a wild species of rice, is a useful genetic
source since it has a habit of early-morning flowering
and high transpiration with sufficient water, both of
which are convenient traits for avoiding heat stress.

26. Rice that can tolerate poor soils
 Nutritional imbalances such as potassium and zinc
deficiency and iron and aluminum toxicity are
widespread in most rice production areas in Asia,
Latin America, and Africa. Genetic donors for
tolerance of these soil problems are being identified
and used in breeding.
 Iron toxicity is a widespread growth constraint in
lowland rice in Africa. IRRI has identified highly
tolerant varieties or lines such as Suakoko 8 (O.
sativa) and CG 14 (O. glaberrima). The Africa Rice
Center (AfricaRice), IRRI’s partner in the region, has
facilitated the release of some improved varieties that
are tolerant of iron toxicity.

27. PESTS AND DISEASES
TOLERANT RICE
 Rice productivity is hampered by a number of
diseases and insects.
 Using plant protection chemicals is not the sustainable
and economic ways of increasing protection
 Breeders, by utilizing the vast genetic resources have
released varieties resistant to certain pests and
diseases.
 Techniques like marker assisted selection has speed
up the process.

30.  To date, approximately 70 resistance genes against
hoppers have been identified, and most of these
genes have been tagged with molecular markers.
Recently six genes for resistance to brown
planthopper (BPH) in different lines have been cloned
using map-based cloning.
 Marker-assisted selection (MAS) and pyramiding of
genes for resistance to BPH and green rice
leafhopper (GRH) have shown higher level and wide
spectrum of resistance than their monogenic lines. In
addition, transgenic approaches including RNAi have
targeted various plant lectins and volatile compounds
to generate resistance to hoppers.

34. Bt RICE
 BT rice is modified to express the cryIA(b) gene of
the Bacillus thuringiensis bacterium.
 The gene confers resistance to a variety of pests including
the rice borer through the production of endotoxins. The
Chinese Government is doing field trials on insect
resistant cultivars. The benefit of BT rice is that farmers do
not need to spray their crops with pesticides to control
fungal, viral, or bacterial pathogens. Conventional rice is
sprayed three to four times per growing season to control
pests.
 Other benefits include increased yield and revenue from
crop cultivation.
 China approved the rice for large-scale use as of 2009

35. C4 RICE
 Rice with a built-in fuel injector to better convert sunlight
into grain, potentially resulting in up to 50% higher
production all while using less water and nutrients.
 “Rice is the staple food for millions across the developing
world, so finding a way to double the amount each plant
produces would help to feed many more of the very
poorest. This new funding will enable the International
Rice Research Institute to begin producing prototypes of
this ‘super rice’ for testing. This could prove a critical
breakthrough in feeding an ever-growing number of hungry
mouths.”
 C4 rice research, currently in its early phases, hopes to
develop a new type of rice with improved photosynthesis
capacity, known as C4.

36.  C3 photosynthesis is inefficient at converting inputs to
grain, as opposed to the C4 pathway, in which
resources are processed more efficiently and
converted into higher grain production.
 The researchers have already identified crucial genes
needed to assemble C4 photosynthesis in rice,
defined the basic elements required for functional C4
photosynthesis, and successfully introduced 10 out of
the 13 genes needed for C4 rice.

37. GREEN SUPER RICE
 From a global viewpoint, a number of challenges need to be
met for sustainable rice production:
(i) increasingly severe occurrence of insects and diseases and
indiscriminate pesticide applications;
(ii) high pressure for yield increase and overuse of fertilizers;
(iii) water shortage and increasingly frequent occurrence of
drought; and
(iv) extensive cultivation in marginal lands.
 A combination of approaches based on the recent advances in
genomic research has been formulated to address these
challenges, with the long-term goal to develop rice cultivars
referred to as Green Super Rice.
 Green Super Rice should possess resistances to multiple
insects and diseases, high nutrient efficiency, and drought
resistance, promising to greatly reduce the consumption of
pesticides, chemical fertilizers, and water.

38.  The International Rice Research Institute (IRRI), together with
the Chinese Academy of Agricultural Sciences (CAAS) and the
Bill & Melinda Gates Foundation (BMGF), collaborate through
funding and research efforts to develop Green Super Rice
(GSR), a new set of rice varieties that perform well under the
toughest conditions.
 GSR is a mix of more than 250 different potential rice varieties
that can adapt to difficult growing conditions such as drought
and low inputs. The lines also use less fertilizer and no
pesticides, which reduces the need for herbicides.
 At present, more than 130 advanced breeding lines with these
traits are undergoing national varietal testing and will soon be
released in different countries as new varieties.
 As of August 2017, 42 GSR varieties have been developed and
have been made available in 11 countries in South Asia,
Southeast Asia, and East and South Africa.

39. FOCUS OF GSR
 The GSR project has five main focuses (Zhang et al. 2018):
 (1) development and improvement of the theoretical and
technical systems for GSR breeding. These systems and
technologies were established at the population, individual, trait,
and genome levels
 (2) establishmentof whole-genome selection platforms based on
the recent developments/findings in the rice functional genomics
research worldwide,
 (3) development of new germplasm resources by pyramiding of
genes of green traits, including development of novel
germplasms with improved resistances to multiple abiotic
(primarily drought) and biotic stresses, high water and nutrient-
use efficiencies, and high grain yield and quality;
 (4) breeding of new GSR cultivars (both inbred and hybrid) with
various combinations of green traits, improved grain yields and
quality;

40. 4 MAIN TYPES
(1) Water -saving and drought-resistant (WDR) cultivars that
have the same or better grain yield and quality as the
current check varieties under the normal irrigated
conditions but yield 30% or more under the water-deficit
or drought conditions;
(2) Nutrient use- efficient (NUE) cultivars that show the
same or better grain yield and quality as the current
check varieties but with 30% of less fertilization (nitrogen
and/or phosphorus) application;
(3) Pest -resistant cultivars that have significantly enhanced
pest resistance to one or more key pests (with a 30% or
more reduction in pesticide application); and
(4) Stress (salt, alkalinity, cold, heat, etc.)-tolerant cultivars
that have the same or better grain yield and quality as
the current check varieties under the non-stress
conditions but yield 30% or more than the checks under
the stress conditions.

41. Schematic representation of combinations of genes
and approaches
for the development of GSR

42.  By combining multi-omics such as genomics,
phenomics, epigenetics, metabolomics, proteomics,
and transcriptomics, the desirable genes in the wild
and cultivated rice species were mined and identified
through large-scale and highthroughput phenotypic
analyses on the re-sequenced rice germplasm
(including wild species) accessions. A series of near-
isogenic lines (NILs) or introgression lines (ILs) with
the elite genetic backgrounds (widely planted major
rice varieties and hybrid parents) that contain only
small genomic segments (e.g., about 200 kb) of target
genes were created through the whole-genome
selection platform
 Introgression breeding scheme in which large-scale
crossing and massive repeated backcrossing to one
(or more) elite parent are performed to generate NILs
with the desirable traits or genes

43. Pre -GSR lines or GSR varieties were
developed in a two-stage process.
 In the first stage, elite lines carrying a single gene of
interest were developed and thoroughly evaluated for
the green traits, which by themselves were useful as
pre-breeding GSR lines.
 Second, the genes introduced into these lines would
be combined in a designed way to develop cultivars
with favorable traits. The introgression breeding
approach has been used for developing GSR, and
demonstrates being robust in several successful
applications.

44.  This approach resulted in many GSR varieties and
their adoption across Asia and Africa in the IR64,
Huanghuazhan (HHZ), and Weed Tolerant Rice
1(WTR1) recipient backgrounds
 Green Super Rice is already in the hands of national
agricultural agencies in key rice-growing countries for
testing and development.
 The project has also identified drought-tolerant GSR
lines with IR64 as the recurrent parent. For example,
IR83142-B-19-B, a GSR line, performs better than
Sahbhagi dhan under drought and zero-input (which
means no fertilizers and no pesticides, and only one
manual weeding) conditions

46.  This integrates strong phenotypic selection in a
modified BC breeding procedure with highly efficient
QTL network discovery by selective introgression and
DNA markers, followed by efficient development of
GSR varieties by designed QTL pyramiding (DQP)
and molecular recurrent selection (MRS).
 This breeding strategy has been demonstrated by
developing large numbers of promising GSR lines with
good tolerances to multiple abiotic stresses from a
small number of breeding populations in a short
period of 6 years and by releases and up-scaling of
13 GSR varieties in Asia.

50. CONCLUSION
 Sustainable rice production is the key to food security
and poverty alleviation of many Asian and African
countries, particularly under changing climatic
conditions. Rice productivity is low in the rainfed areas
of Asia and Africa, particularly in the face of the global
climate change.
 Breeding programmes such as GSR signal a major
shift in breeding objectives from emphasizing yield
improvement in the past to high yield potential plus
resilience to more frequent and extreme
environmental disturbances from climatic changes in
the future.

51. REFERENCES
 Li, Zhikang & Ali, Jauhar. (2017). Breeding green super rice
(GSR) varieties for sustainable rice cultivation.
10.19103/AS.2016.0003.05.
 Khush, G.S. (2015). Breeding Rice for Sustainable Agricultural
Systems. In International Crop Science I (eds D. Buxton, R.
Shibles, R. Forsberg, B. Blad, K. Asay, G. Paulsen and R.
Wilson). doi:10.2135/1993.internationalcropscience.c31
 Yu, S., Ali, J., Zhang, C. et al. Genomic Breeding of Green
Super Rice Varieties and Their Deployment in Asia and Africa.
Theor Appl Genet 133, 1427–1442 (2020).
https://doi.org/10.1007/s00122-019-03516-9
 Zhang, Q. Strategies for developing green super rice. Proc.
Natl. Acad. Sci. USA 104, 16402–16409 (2007).
 http://www.irri.org
 http://ricestat.irri.org/mistigtrng/demos/php/cssdiv_gsr.php
 http://news.irri.org/2019/04/green-super-rice-varieties-are-