CREES scientists will be conducting research on the islands’ local varieties of papayas, one with red flesh dagua and one with yellow.
Red-fleshed papayas are favorable among the farming community; however, they are susceptible to the virus.
CREES scientists will be studying virus-resistant characteristics of yellow-fleshed tolerant variety of papayas, which still produce fruit in spite of infection.
Those resistant characteristics will then be transferred into red-fleshed papayas through traditional breeding and genetic methods.
The virus, known as the papaya ringspot virus, develops microscopic ring-like extensions, which appear as dots and streaks on the fruit’s skin.
The virus also causes malformations in plant’s stem, petioles, and leaves.
The competitive grant, which was issued by the U.S. Department of Agriculture, funds a program titled “Improvement of Papaya Cultivars from the Mariana Islands for Uniformity and Papaya Ringspot Virus Tolerance.”
The Marianas aspect of the project is led by a collaborative effort between CREES and University of Guam plant pathologist professor George Wall.
Heading the Saipan research group is Dr. Dilip Nandwani, who is a plant pathologist at CREES and program leader for crop production and improvement.
This is one of the several research projects with Nandwani currently ongoing on banana, taro, sweet potato, coconut and dao’k.
According to Nandwani, the development of a tolerant species will require about six to seven years of research, as studies must be conducted on six to seven generations of samples of papaya, a plant that produces fruit within a year planting.
UOG, which has been engaged in the project for nearly two years, has given CREES some seeds from its first generation samples.
“With the samples we have received from UOG’s first generation, we will be able to commence our research with prior findings and observations,” said Nandwani.
“With the proper experiments and studies, we will be able to release our fourth generation plants to commercial farmers.”
In 1995, scientists in Hawaii developed virus resistant transgenic papayas through genetic engineering techniques.
However, this type of papaya cannot be legally grown in the Marianas due to strict regulations and patent rights in the state of Hawaii.
“With the elimination of male plants and plants with deformed fruits, we can look forward to produce a larger supply of virus-resistant papayas through breeding program” Nandwani said.
“This research is yet another example of NMC’s efforts to assist the community in battling agricultural menaces,” said Tee Abraham, dean of Community Programs and Services. “We will continue to offer assistance, guidance, and resources to the community through extensive research and study.”
