text: This was the first plant in which the role of Brassinosteroids in sex determination was proven.
full_question: This was the first plant in which the role of Brassinosteroids in sex determination was proven. A 2018 paper in Science challenged the single-origin theory of this plant, citing evidence of South American hybrids between this organism and teosinte. A scientist noted that broken ninth chromosomes in these plants caused abnormal leaf coloration in different patterns between two generations, leading to the discovery of transposable elements. Barbara McClintock studied, for 10 points, what staple crop first cultivated in the Americas?
first_sentence: This was the first plant in which the role of Brassinosteroids in sex determination was proven.