Attractant and Oviposition Stimulant of Crataeva religiosa Forst. to Pieris rapae

We were aimed to confirm the oviposition preference of P. rapae against C. religiosa (Capparidaceae plant) and cabbage (Brassicaceae plant) and then analyzed the AITC and sinigrin contents and myrosinase activity in these plants to clarify the attractant and oviposition stimulant properties of C. religiosa and cabbage to P. rapae. We analyzed the attractant and oviposition stimulant of a Brassicaceae plant, Brassica oleracea var. capitata L. (cabbage) and a Capparidaceae plant, Crataeva religiosa to Pieri srapae crucivora Boisduval by the oviposition preference test. The oviposition preference of P. rapae was the highest in cabbage, followed by C. religiosa, but the lettuce (control plant) was rarely selected. Allylisothiocyanate (AITC), which is assumed to be one of the attractant and sinigrin as oviposition stimulants were detected in cabbage using GC-MS. Their compounds were not detected in C. religiosa, but the higher content of methylisothiocyanate (MITC) that is analogous to AITC was found. Myrosinase activity was analyzed by HPLC and detected in cabbage and C. religiosa, but not in lettuce. Glucosinolate of sinigrin analogous in C. religiosa fractionated by HPLC was decreased by myrosinase treatment and then produced MITC. We identified that this compound was glucocapparin as a precursor of MITC by LC-MS. These results revealed that C. religiosa have a glucosinolate-myrosinase metabolic system and pathway.