Gov’t em­barks on ‘ge­netic diver­sity’ pro­gram on narra

The Philippine Star - - AGRICULTURE -

The govern­ment has em­barked on a ro­bust “ge­netic diver­sity” pro­gram of the en­dan­gered narra and in­dus­trial tree rat­tan as a com­mit­ment to con­serve forests amid seem­ingly ir­re­versible de­for­esta­tion that threat­ens eco­nomic re­sources.

The Ecosys­tems Re­search & De­vel­op­ment Bureau (ERDB) has started car­ry­ing out DNA anal­y­sis of these eco­nom­i­cally im­por­tant tree species as a long term sup­port to the DENR’s na­tional green­ing pro­gram (NGP).

Ge­netic vari­a­tion is the ba­sis of evo­lu­tion and the cat­a­lyst for species to adapt to the ever chang­ing en­vi­ron­ment.

“As­sess­ment of ge­netic vari­a­tion among and within pop­u­la­tions is es­sen­tial for the suc­cess of any tree breed­ing and se­lec­tion pro­grams. It holds vast po­ten­tials for the preser­va­tion of the for­est ecosys­tems,” said ERDB di­rec­tor Sofio Quin­tana.

Six prov­inces – Ilo­cos Sur, Cebu, Iloilo, Marinduque, Nueva Viz­caya and Que­zon— have so far been iden­ti­fied as po­ten­tial sources of good plant­ing ma­te­ri­als for narra re­for­esta­tion.

“The ge­netic diver­sity anal­y­sis showed that the six pop­u­la­tions of Pte­ro­car­pus in­di­cus Wild (narra) from the six prov­inces have good lev­els of ge­netic vari­a­tion and can serve as good sources of po­ten­tially use­ful genes,” said ERDB ge­netic ex­perts.

The govern­ment has deemed a top pri­or­ity to con­serve forests as a top eco­nomic as­set as Philip­pines has among the most bi­o­log­i­cally di­verse flora with five per­cent of the world’s to­tal.

Narra’s tim­ber is prom­i­nent among im­porters in Asia, Europe, US and Aus­tralia which “ac­cept large vol­umes of sawn tim­ber at high prices of $600 per cu­bic me­ter ac­cord­ing to the “Species Pro­files for Pa­cific Is­land Agro­forestry.”

Narra is also known for its medic­i­nal, or­na­men­tal, and ni­tro­gen-fix­ing func­tions.

ERDB’s project, “2018 Ge­netic Diver­sity: A Key Com­po­nent for Con­serv­ing Philip­pine For­est Trees,” aims to iden­tify trees with molec­u­lar mark­ers that in­di­cate high sur­vival rate as part of plant­ing the tar­geted 1.5 bil­lion trees un­der the NGP.

“With the in­crease in global av­er­age tem­per­a­tures, some species of for­est trees fail to cope with such changes. With more ge­netic vari­a­tions, it is more likely that some in­di­vid­u­als pos­sess al­le­les (al­ter­na­tive form of genes) that bet­ter suit the en­vi­ron­ment,” the ERDB said.

Hav­ing less ge­netic diver­sity leads to uni­for­mity, with pop­u­la­tion hav­ing in­di­vid­u­als less likely to adapt and sur­vive in the chang­ing en­vi­ron­ment.

While mono­cul­ture in agri­cul­ture is good for har­vest­ing a good vol­ume of a sin­gle crop, it will be a prob­lem when a dis­ease or par­a­sites at­tack the field in the long run.

Lit­tle ge­netic vari­a­tion within species im­pedes the process of healthy re­pro­duc­tion as ev­i­denced by the ex­pres­sion of harm­ful traits in the off­spring re­sult­ing from in­breed­ing (mat­ing of ge­net­i­cally re­lated or­gan­isms or in hu­man, within one fam­ily).

In­bred trees which grow slowly are of­ten de­formed and many die sud­denly and in­ex­pli­ca­bly be­fore reach­ing ma­tu­rity. Few in­bred trees sur­vive and re­pro­duce in nat­u­ral for­est set­ting.

In 1890, an epi­demic had spread across Panama wip­ing out hectares of ba­nana pro­duc­tion. Be­ing ge­net­i­cally iden­ti­cal, ba­nana plants are sus­cep­ti­ble to the fun­gal dis­ease, pro­vid­ing lit­tle to no re­sis­tance against the dis­ease.

Such sce­nario ul­ti­mately leads to ex­tinc­tion of the pop­u­la­tion and even­tu­ally ex­tinc­tion of the species.

“Knowl­edge of the ex­tent of ge­netic diver­sity in se­lected narra pop­u­la­tions may be used in de­ter­min­ing the sus­cep­ti­bil­ity of these narra pop­u­la­tions to pests like the am­brosia bee­tles which are the causative agent of fusar­ium wilt (Fusar­ium oxys­po­rum),” the ERDB said.

Forestry ex­perts use molec­u­lar mark­ers as part of ef­fec­tive re­for­esta­tion strat­egy be­cause of the “ease, ra­pid­ity and re­li­a­bil­ity in pro­duc­ing re­sults.

In or­der for plant ge­neti­cists to dis­tin­guish ge­netic vari­a­tions, they use seg­ments of DNA (de­oxyri­bonu­cleic acid) se­quence of the in­di­vid­u­als to mine them out de­spite the lim­ited avail­abil­ity of whole genome se­quences from for­est trees species.

Af­ter col­lect­ing the plant ma­te­rial (leaf, stem, or root), care­ful op­ti­miza­tion of pro­to­cols fol­lows wherein the DNA of the ma­te­rial is iso­lated. This process is called DNA ex­trac­tion. The process in­volves break­ing the cell wall and cell mem­brane (cell ly­sis), re­mov­ing the or­ganelles, and de­stroy­ing the nu­clear mem­brane. Af­ter these pro­cesses, the “purest” DNA can be ex­tracted.

Hav­ing a de­sir­able amount of DNA with su­pe­rior pu­rity, molec­u­lar bi­ol­o­gists then sub­ject this DNA to a tem­per­a­ture sen­si­tive process that pro­duces mil­lions of copies of it in a mat­ter of an hour or two. This copy­ing process is called DNA am­pli­fi­ca­tion or poly­merase chain re­ac­tion (PCR) dis­cov­ered by No­bel Prize win­ner Kary Mullis in 1985.

It in­volves a se­ries of heat­ing-cool­ing-heat­ing the DNA. The tem­per­a­ture changes al­low the en­zymes and other reagents to copy the tar­get re­gions (molec­u­lar mark­ers) of the DNA.

PCR is an in­dis­pens­able tech­nique known to be used in med­i­cal and clin­i­cal lab­o­ra­tory re­search in­clud­ing foren­sic sci­ence in crime scene in­ves­ti­ga­tions.

It also holds a po­ten­tial swing in im­prov­ing foren­sic botany for higher pro­duc­tiv­ity and sur­viv­abil­ity of for­est trees species and for the trees to achieve su­pe­ri­or­ity in growth pa­ram­e­ters.

Newspapers in English

Newspapers from Philippines

© PressReader. All rights reserved.