The first gene-sequenced crop is :

The correct option is Rice.

To understand why rice was the first crop plant to have its genome fully sequenced, we can look at the following key factors:
1. Model Organism for Cereal Crops: Rice (Oryza sativa) is a member of the grass family (Poaceae), which includes other globally vital food crops such as wheat, maize, barley, and rye. Because these crops share a high degree of genetic similarity (synteny), rice serves as an ideal model organism to study and understand the genetics of all cereal crops.
2. Relatively Small Genome Size: Compared to other major crops, rice has a relatively small and compact genome. Its genome consists of approximately 389 million base pairs (Mb), distributed across 12 chromosomes. In comparison, the genome of maize is about 2,500 Mb, and the genome of wheat is extremely large and complex at approximately 17,000 Mb. This smaller size made rice the most practical candidate for complete genome sequencing using the technology available at the time.
3. International Collaboration: The sequencing effort was led by the International Rice Genome Sequencing Project (IRGSP), a joint collaboration of research centers from multiple countries. Draft sequences were published in 2002, and the high-quality, finished sequence of the rice genome was officially completed and published in 2005, marking the first time the genome of a major food crop was fully mapped.