Investigation and evaluation of color leaf germplasm resources of Pistacia chinensis in Hebei Province of northern China

Objective This paper conducts a systematic investigation and evaluation of the colored-leaf germplasm resources of Pistacia chinensis in Hebei Province of northern China, and screens superior germplasms of different color series of P. chinensis, in order to lay a foundation for the breeding of new colored-leaf varieties of Pistacia chinensis and to provide an important basis for the landscape configuration of Pistacia chinensis.

Method With Baoding City and Wu’an City of Hebei Province as the study areas, data on color transition period of various germplasms of P. chinensis were obtained through field investigations, and compound leaf samples were collected; photographs were taken of the leaves, partial canopy, and individual or multi-tree combination landscapes of P. chinensis; the leaves were compared with the national standard color chart to determine leaf colors, which were classified into color series; the scenic beauty estimation (SBE) method was applied to evaluate typical leaves, partial canopy, and individual or multi-tree combination landscapes of P. chinensis, and superior germplasms of different color series of P. chinensis were screened.

Result (1) A total of 36 germplasms had almost completed the whole-plant color transition by October 14 (inclusive); 75 germplasms started color transition between October 15 and 22; 9 germplasms started color transition after October 22. (2) In this study, the leaf colors of P. chinensis were divided into four categories: red series, orange series, yellow series, and variegated class. In the evaluation of leaves, 12 germplasms (57%) had positive overall SBE scores, indicating these germplasms had relatively high ornamental value in their leaves; the top two highest-scoring germplasms belonged to the red series, namely LGC56 and LGC53. In the evaluation of partial canopy, the five germplasms including WuC1 of the orange series and K85, A14, WuR1, and K29 of red series had relatively higher ornamental values. In the landscape evaluation of P. chinensis, the highest-ranked was individual landscape K47, which belonged to red series; among the combination landscapes, the highest-ranked corresponded to the red-orange-yellow colors, with the landscape labeled as WuRCY.

Conclusion The color transition period and color series types of P. chinensis in Hebei Province are diverse; the red series germplasms LGC56, LGC53, LGC55, K47, WuR1, and K29, and the orange series germplasms 3-1, K91, and WuC1 exhibit high ornamental values. The research results will lay an important foundation for breeding, application, and industrial promotion of superior germplasms of P. chinensis, and are expected to promote the development of native colored-leaf tree species and enrich colored-leaf seedling market.