Question

Semi-dwarf rice variety $IR-8$ was developed by
a. Taiwan
b. Philippines
c. India
d. China

Answer 1

Semi-dwarf rice variety $IR-8$ was developed by the International Rice Research Institute (IRRI). They developed this high yielding rice variety by crossbreeding between parents of two different rice varieties belonging to different countries. This rice is also known as miracle rice as it helped fight famine.

Complete answer:
- $IR-8$ was the crossbred variety. It was produced by the cross-breeding of two different varieties of rice.
- The crossbreeding includes one parent from Indonesia, Peta which has characteristics of high yielding and another parent from Taiwan which was the dwarf variety.
- In the production of gibberellin, the semi-dwarf gene-1 which affects the plant height encodes an enzyme. This semi-dwarf gene-1 improves the yield of rice variety.
- Though this variety was successful and well suited in the areas at the time of monsoon this variety does not fit. The taste and texture were also not good as it was chalky and also hardens after cooking.

Also,

China- the largest producer of rice in the world is China. The rice varieties grown in China are Golden Shuttle 1 and Zhongyu 1, 4, and 6.

India- India is one of the world's largest producers of white, brown rice. Some of the rice varieties grown in India are Padma, Bala, Jayanti, Shakti, etc.

Hence, the correct answer is option (B).

Note: The $IR-8$ rice variety which was developed, increases the yield double. Also in some reports, it was said that it increased the yield ten times as $IR-8$ was better than the normal rice. Its reach spreads rapidly throughout Asia and the problem of famine was prevented.