REPORT ON PROVENANCE COLLECTIONS OF PINUS OOCARPA Schiede
AND PINUS PATULA Schl. et Cham. IN MEXICO, 1972/73

by

Instituto Nacional de Investigaciones Forestales
Departamento de Mejoramiento de Arboles Forestales
Mexico

INTRODUCTION

Following recommendations given by the FAO Panel of Experts on Forest Gene Resources, funds were transferred by FAO to Instituto Nacional de Investigaciones Forestales (INIF), Mexico, in October 1971 and January 1973. The purpose of the contribution was to expand the Mexican programme of exploration and range-wide sampling of provenances of important forest tree species in Mexico as identified by the FAO Panel at its first and second sessions. According to the agreement between INIF and FAO first priority was to be given to provenance collections of Pinus oocarpa Schiede and Pinus patula Schl. et Cham.

SEED COLLECTION

General

After some preliminary planning collection work was initiated in January 1972. Two collection teams were formed at that time, both supervised by a university trained forestry officer and consisting of one forest technician and eight climbers. Both teams were fully equipped.

Methods of Collection and Extraction

All collections were made from healthy trees in natural stands using Tree Bicycles. Careful identification of species was made before collection. The cones collected were sent in jute sacks to the central storage facilities of INIF in Mexico City, where they were sun-dried. The seed was then mechanically extracted and cleaned, and treated with Captan before storage at approximately 0 – +3°C and at an average moisture content of 8%. All seedlots were tested according to the rules established by the International Seed Testing Association (ISTA).

Details of each seed collection are in Table 1 and the location of each collection site is shown on the attached map.

PINUS OOCARPA Schiede

Distribution

The species occurs in Mexico from the Guatemalan border in the south (approx. 15°N Lat.) to the State of Sonora in the north (approx. 28°N Lat.), in the western states of the country. In the central parts it is found in the states of México, Guanajuato and Morales, in the eastern parts in the states of Puebla, Hidalgo and Veracruz.

Provenances collected

Because of the vast areas concerned it was decided to collect in two stages, visiting first the states of Chiapas, Oaxaca, Guerreo, Mexico, Michoacán and Jalisco, and during the second stage the states of Sonora, Chihuahua, Durango, Sinaloa, Nyarit, Hidalgo, Veracruz and Zacatecas.

Five provenances were collected in 1972 and an additional five provenances in early 1973. (see table 1 and map on page 31).

One provenance was collected of Pinus oocarpa var. ochoterenai Mart.

PINUS PATULA Schl. et Cham.

Distribution

The species occurs in Mexico in the states of Tamaulipas, Queretaro, Hidalgo, Puebla, Tlaxcala and Veracruz, approximately 18°20'–23°50'N Lat. and 96°50'–99°40'W. Long.

Provenances collected

Because of the poor cone crop only one provenance was collected in 1972 and two provenances in early 1973 (see table 1 and map on page 31)

Three additional localities were visited in order to collect provenances of Pinus patula var. longepedunculata Loock. (distribution approx. 17–18° N Lat. and 96°20'–97°00'W Long.) but because of the poor cone crop no seed was collected.

FUTURE PROGRAMME

The collections will be continued until enough seed is available for the establishment of range-wide provenance trials of the two species. 18 countries have expressed their wish to participate in international provenance trials of Pinus patula, and 27 countries are already participating in international trials of central American provenances of P. oocarpa, for the collection and coordination of which the Commonwealth Forestry Institute, Oxford is responsible - an indication of the strong interest already being shown in this species.

Table 1
MEXICAN PROVENANCE COLLECTIONS. SEEDLOTS COLLECTED IN 1972/73

* Not yet available

APPENDIX I - MEXICAN SEED COLLECTIONS 1972–73