1. Dr. P.Raghuveer Rao National conference of plant physiology-2013 on
“current trends in plant biology research”
December 13-16,2013,Junagadh,Gujarat.
Dr. P.Raghuveer Rao
Senior Scientist
Plant Physiology
Directorate of rice research
Rajendranagar-hyderabad

2. Research Activities at DRR
Lead Research
Externally Funded Projects
AICIRIP-pl.physiology

3. Major advances have occurred in rice production due to adoption of green revolution technology. Between 1966 and 2000, the population of densely populated low income countries grew by 90% but rice production increased by 130% from 257 million tons in 1966 to 600 million tons in However, the population of rice consuming countries continues to grow and it is estimated that we will have to produce more rice in This increased demand will have to be met from less land, with less water, less labour and fewer chemicals. To meet the challenge of producing more rice from suitable lands we need rice varieties with higher yield potential and greater yield stability. Various strategies for increasing the rice yield potential being employed include: (1) conventional hybridization and selection procedures, (2) ideotype breeding, (3) hybrid breeding, (4) wide hybridization and (5) genetic engineering. Various conventional and biotechnology approach are being employed to develop durable resistance to diseases and insect and for tolerance to abiotic stresses. The availability of the rice genome sequence will now permit identification of the function of each of 60,000 rice genes through functional genomics. Once the function of a gene is identified, it will be possible to develop new rice varieties by introduction of the gene through traditional breeding in combination with marker aided selection or direct engineering of genes into rice varieties.
What it will take to feed 5.0 billion rice consumers in 2030

4. Ideotype breeding
Ideotype breeding aimed at modifying the plant architecture is a time tested strategy to achieve increases in yield potential. As an example selection for short stature cereals such as wheat, rice and sorghum resulted in doubling of yield potential. Introduction of sd1 gene for short stature into rice led to improvement in harvest index from 0.3to 0.5 and increases in biomass production.
To increase the yield potential of rice further, anew plant type was conceptualized in Modern semi-dwarf rices produce a larger number of un productive tillers and excessive leaf area which cause mutual shading and reduce canopy photosynthesis and sink size, especially when they are grown under direct sowing conditions. To increase the yield potential of these semi-dwarf rices furthermore scientists proposed further modifications of plant architecture with following characteristics:
• Low tillering (9–10 tillers when transplanted) • No unproductive tillers
• 200–250 grains per panicle • Dark green and erect leaves
• Vigorous and deep root system
Breeding efforts to develop ‘‘New Plant Type’’(NPT) were initiated in The objective was to develop improved germplasm with 15–20% higher yield than that of existing high yielding varieties. Numerous breeding lines with desired ideotype were developed (Khush, 1995) and were shared with national rice improvement programs. ThreeNPT lines have been released in China and one in Indonesia. Other NARS (National Agricultural Research Systems) are evaluating and further
improving the NPT lines.

5. Increasing the Yield Potential of Rice
Various strategies for increasing the yield potential of rice includes
conventional hybridization and selection procedures,
Ideotype breeding,
Heterosis breeding,
Wide hybridization,
Genetic engineering.   

9. ILS Introgressed lines Germplasm Tropical Jopanicas HYV/Hybrids 1
13- 7
MSP-1 19
E- 2710 34
TJP- 20 59
NDR 359 2
S-40
MSP-2 20
E- 2729 35
TJP- 138 60
PHB- 71 3
50- 13
MSP-3 21
E- 2857 36
TJP- 139 61
DRRH- 3 4
248(S)
MSP-4 22
E- 2875 37
TJP- 142 62
Dhana Rasi 5
S- 40
MSP-5 23
E- 2940 38
TJP- 150 63
KRH- 2 6
RPHR- 517
MSP-6 24
E- 3067 39
TJP- 157 64
Rasi 7
RPHR- 1005
MSP-7 25
E- 3082 42
TJP- 197 65
Jaya 8
RPHR- 1096
MSP-8 26
E- 3118 43
TJP- 198 66
Vijetha 9
IBL- 57
MSP-9 27
E- 3127 45
TJP- 4 67
Jarva 10
Swarna (Check)
MSP-10 28
E- 3138 47
TJP- 34 68
Sampada 11
MSP-11 29
E- 3173 50
TJP- 27 69
PA 6444 12
MSP-12 30
E- 3287 51
TJP- 82 70
MTU 1010 13
MSP-13 31
E- 3321 52
TJP- 58 71
Akhanphou 14
MSP-14 32
E- 3324 54
TJP- 229 72
IR 72 15
MSP-15 33
E- 3325 56
TJP- 224 16
MSP-16 57
TJP- 5 17
MSP-17 18
MSP-18
KMR3 x
O.rufipogan
Swarna x
O.nivara
Restorers/
R-lines

10. average of all harvested areas in China
Average annual yield of rice per unit land area in China. Each data point is the
average of all harvested areas in China

11. Variation in leaf photosynthetic traits in divergent rice genotypes under field condition
S.No.
Parameter df
MSS F
ProbF
Range 1
Rate of Photosynthesis
( PN )
106
4.79
19.94
2.583E-40** 2
Stomatal conductance (gs)
0.10
8.26
1.918E-23** 3
Intercellular CO2 Concentration
4.51
1.225E-13** 4
Transpiration Rate (E)
16.21
15.12
8.67E-35** 5
Ci/Ca ratio
0.01
4.33
4.581E-13** 6
Water Use Eficiency (PN/E)
0.39
8.75
1.80E-24** 7
Intrinsic Water Use Efficiency)
416.58
4.49
1.49E-13** 8
Carboxylation efficiency
0.00
16.00
6.66E-36**

12. Variation in Photosynthetic efficiency [µmol (CO2)m-2s-1 ] in different groups of rice
Mean
Range df
MSS F
ProbF
AVT-1-ME (16)
23.74 14
5.17
4.128
0.0047***
Hybrids (8)
21.27 6
25.64
4.573
0.032**
Germplasm/Landraces (24)
13.97 22
43.24
40.244
1.44E-13***
Introgressed lines(10)
14.74 8
16.94
15.239
***
Tropical Japonica (20)
23.60 18
65.62
6.2262
8.4E-05***
Released Varieties (30)
16.49 28
44.21
20.205
6.5E-11***
** (P<0.01); *** (P<0.005)

13. Variation in photosynthesis in selected germplasm/land races

14. Variation in PN and gs in different groups of rice

15. Variation in photosynthesis rate in selected varieties of rice (Kharif-2012)

16. Variation in leaf photosynthetic traits among different wild rice species and cultivated varieties. Each value represents the mean of the respective species.

33. Thank you