A blog maintained by Tevita Kete, PGR Officer
Secretariat of the Pacific Community (SPC), Suva, Fiji Islands
This weblog documents the activities of Pacific Agricultural Genetic Resources Network (PAPGREN), along with other information on plant genetic resources (PGR) in the Pacific.
The myriad varieties found within cultivated plants are fundamental to the present and future productivity of agriculture. PAPGREN, which is coordinated by the Land Resources Division of the Secretariat of the Pacific Community (SPC), helps Pacific countries and territories to conserve their crop genetic diversity sustainably, with technical assistance from the Bioversity International (BI) and support from NZAID and ACIAR.
SPC also hosts the Centre of Pacific Crops and Trees (CEPaCT). The CEPaCT maintains regional in vitro collections of crops important to the Pacific and carries out research on tissue culture technology. The CEPaCT Adviser is Dr Mary Taylor (MaryT@spc.int), the CEPaCT Curator is Ms Valerie Tuia (ValerieT@spc.int).
PAPGREN coordination and support
Mr William Wigmore
Mr Adelino S. Lorens
Dr Lois Englberger
Mr Apisai Ucuboi
Dr Maurice Wong
Mr Tianeti Beenna Ioane
Mr Frederick Muller
Mr Herman Francisco
Ms Rosa Kambuou
Ms Laisene Samuelu
Mr Jimi Saelea
Mr Tony Jansen
Mr Finao Pole
Mr Frazer Bule Lehi
Interested in GIS?
Tuesday, February 08, 2005
Posted 2:19 PM by Luigi
Traditional farmers select heterozygous cassava
An interesting study on cassava from the Amazon which could have relevance to other root crops, including in the Pacific.
Few studies quantify evolutionary processes in populations of domesticated plants in traditional farming systems. In February's Ecology Letters, Pujol, David and McKey show that these systems offer unusual opportunities for studying microevolution. Cassava (Manihot esculenta) is clonally propagated, but Amerindian cassava farmers also regularly incorporate volunteer plants from sexually produced seeds into their clonal stocks (cuttings) at harvest time. These new genotypes renew diversity lost under clonal propagation.
However, whereas multiplied clones are highly heterozygous, many of the volunteer plants are inbred. How does high heterozygosity persist despite their incorporation? The authors demonstrate a novel case of selection for heterozygosity that explains this paradox, showing that humans inadvertently favour heterozygous volunteers.
When farmers weeded fields, they killed small volunteers, but retained large ones, which were also the most heterozygous. Demonstrating heterosis in nature usually requires large samples, but novel features of this system allowed escape of this constraint.
* Comments:Post a Comment
Agrobiodiversity Weblog: For discussions of conservation and sustainable use of the genetic resources of crops, livestock and their wild relatives.