1. Morphological Characteristics of High Yielding Rice Varieties

2. Why Rice is Important to us?
World’s most important food crop
A primary source of food for more than half of the world’s population
>90% of the world’s rice is grown and consumed in Asia
Rice accounts for % of the calories consumed by more than 3 billion Asians
Planted 154 million hectares annually or on about 11% of the world’s cultivated land.

3. Need of new improved verities
Total requirement can not supply by traditional rice varieties
So scientist try to Increase the Yield Potential of Rice

4. Strategies for Increasing the Yield Potential of Rice
Conventional hybridization and selection procedures
Ideotype breeding
Heterosis breeding
Wide hybridization
Genetic engineering

5. By those methods the plant morphology is improved
Unhealthy
Healthy canopy

7. Where we can see Changes?
Plant height
Plant leaves
No of tillers per plant
Plant type
Panicle weight and number
Leaf area index
Ratio of leaf area to grains
Harvest Index

8. Morphological Improvement
Several models for super high-yielding rice (new plant type)
main features,
big panicles (250 spike lets per panicle)
fewer tillers (3-4 productive tillers per plant)
short and sturdy culm

9. Plant Height Short and sturdy Culm Ideal height
Semi dwarf cultivars characterized by lodging resistance
Increase nitrogen responsive
Ideal height
Early crop :55-60 cm
late crop :60-76 cm
Generally; 100 cm with culm length of 70 cm

10. Initial Semi-Dwarf Rice Varieties in the world

11. Plant Leaves Tall erect-leaved canopy
The upper three leaf blades should be long, erect, narrow, V-shaped and thick
Long and erect
A larger leaf area receive
Light on both sides
Not put each other in the shade
Light is used more efficiently
Erect leaf canopy before appearance of panicles

12. Relatively small space - higher effective leaf area index The V-shape
Plant leaves cont…
Narrow leaves
Relatively small space - higher effective leaf area index
The V-shape
Makes the leaf blade stiffer and not prone to droopiness
Thick leaves
Have a higher photosynthetic function and are not easily senescent
Flag leaf, length of 50 cm (19.7 in) long and located 20 cm (7.9 in) higher than the top of the panicle
2nd leaf from the top, length is 55 cm (21.6 in) and is located higher than the top of the panicle

13. Ideal length of the first leaf under the top leaf,
Plant leaves cont..
Ideal length of the first leaf under the top leaf,
Early crop: cm
Late crop: cm
Ideal width of the first leaf under the top leaf,
Early crop: cm
Late crop: cm
Ideal length of the second leaf under the top leaf,
Early crop: cm
Late crop: 37-43cm

14. Ideal width of the second leaf under the top leaf,
Plant leaves cont..
Ideal width of the second leaf under the top leaf,
Early crop: cm
Late crop: About 1.1cm
Ideal top leaf angle at the active tillering stage
Early crop: 22-58°
Late crop: 4 12°
Based on these results, a new concept of "dynamic plant type structure"

15. Leaf Angles Flag Leaf: about 5o 2nd leaf : about 10o
3rd leaf: about 20o

16. Leaf Area Index
The greater leaf area index (LAI) with smaller area per stem
Important morphological factor contributing to the high yield

17. Productive Tillers Per Plant
Ideal tiller number per plant,
Early crop: About 15 tillers
Late crop : tillers
Less tillers- less tillers for flowering
More tillers- less no of panicle baring tillers
Rice tiller angle more vertical
Fewer tillers (3-4 productive tillers per plant)

18. Panicle Length With range values of 13.3 – 29.6 cm
Maximum panicle length is contributes positively,
Grain size, grain shape
Higher numbers of tillers/plant
Longer panicles and greater number of grains/panicle ultimately contribute to higher grain yield
Panicle height, top of filled panicle is about 60 cm (23.6 in) from the ground

19. Lower Panicle Position
The tip of the panicle is only 60 to 70 cm above the ground during the ripening stage
The plant to be highly resistant to lodging - an essential character for breeding super high-yielding rice varieties

20. Harvest Index Harvest Index is very high (above 0.5)
Make the stem thicker and sturdier, which usually results in HI decrease,
that it is difficult to obtain super high yield by increasing HI.

21. Morphological Model of Super High-Yielding Rice
Uppermost three leaves:
Flag leaf, long, 50 cm, higher than the panicle top 20 cm
The 2nd leaf from the top: 10% longer than the flag leaf, and over the top of the panicle
The 3rd leaf = the middle position of the panicle
Plant height ; 100 cm, with culm length = 70 cm
Erect: the leaf angles of the flag, 2nd and 3rd leaves are around 5, 10, 20 degrees, till mature
Narrow, V-shape and thick: narrow with 2 cm when flattened

22. Morphological Model cont…
Plant type:
Moderate compact with moderate tillering capacity
Drooping panicles after filled
Above ground ~ 60 cm
Erect-leaved canopy without appearance of the panicles
Leaf area index (LAI) and ratio of leaf area to grains: the LAI is ~ 6.5 based on the uppermost three leaves, the ratio of leaf area to grain weight is 100 : , meaning that to produce grams of rice, 100 cm2 of the upper three functional leaves are needed

23. Panicle weight and number:
Morphological Model cont…
Panicle weight and number:
Grain weight per panicle = 5 g
2.7 million panicles per hectare
Harvest index > 0.55
Leaf area index (LAI) and ratio of leaf area to grains:
The LAI is ~ 6.5 based on the uppermost three leaves
The ratio of leaf area to grain weight is 100 : (meaning that to produce grams of rice, 100 cm2 of the upper three functional leaves are needed)

24. THANK YOU