An Overview of Populus Genetic Resource in

Southwest China

Xueqin WanCollege of Forestry

Sichuan Agricultural University

23rd Session, IPC

Beijing, China 2008-10

ContentsIntroductionIntroductionGeneral situation General situation ResearchResearchApplication Application ConservationConservationSuggestionSuggestionConclusionConclusionOur worksOur works

In this presentation, southwest China refers to the areas covered by west Sichuan, east Tibet and northwest Yunnan.

Introduction

It falls into subtropical zone, and possesses diverse landforms ranging from plateau, mountain, hill to plain with a variation about 3800 meters in altitude. Diverse habitat has fostered abundant poplar genetic resource.fostered abundant poplar genetic resource.

The resource plays an important role on The resource plays an important role on scientific research and practical scientific research and practical application. But it is unfamiliar to the rest application. But it is unfamiliar to the rest of the world, and facing severe threat. of the world, and facing severe threat.

The aim of this presentation is to The aim of this presentation is to introduce the resource to the world, and introduce the resource to the world, and appeal to more people for its appeal to more people for its conservation and application.conservation and application.

Introduction

General situation

SpeciesSpecies

DistributionDistribution

AdaptabilityAdaptability

GrowthGrowth

Species

There are 28 species, 20 varieties, and more There are 28 species, 20 varieties, and more

than 10 natural hybrids in this region. Of than 10 natural hybrids in this region. Of

them, 25 species are endemic to China, and them, 25 species are endemic to China, and

17 species only distribute in the Southwest.17 species only distribute in the Southwest.

So the region is regarded as one of the So the region is regarded as one of the

natural distribution and variation natural distribution and variation centrescentres of of

PopulusPopulus in China. in China. General situation

●, means the species distributes in southwest China. ●, means it is an endemic species to southwest China

Section/Species DSWCbSWCES

c

Sect. Populus

1 P. davidiana Dode ●

2 P. rotundifolia Griff ●

3 P. adenopoda Maxim ●

Sect. Leucoides

4 P. lasiocarpa Oliv. ●

5 P. wilsonii Schneid ●

6 P. glauca Haines ● ●

7 P. pseudoglauca C. Wang et P.Y. Fu ● ●

8 P. gonggaensis N. Chao & J.R. He ● ●

Species

General situation

Sect.Tacamahaca

9 P. simonii Carr. ●

10 P. schneideri (Rehd.) N. Chao ● ●

11 P. lancifolia N. Chao ● ●

12 P. fangiana N.Chao & J. Liu ● ●

13 P. caspica Bornm. ● ●

14 P. przewalskii Maxim. ●

15 P. kangdingensis C. Wang & S.L. Tung ● ●

16 P. cathayana Rehd. ●

17 P.purdomii Rehd. ●

18 P.trinervis C. Wang & Tung ● ●

General situation

Species

Sect.Tacamahaca 19 P. szechuanica Schneid. ● ●20 P. yunanensis Dode. ● ●21 P. qumdoensis C.Wang & S.L. Tung ● ●22 P. mainlingensis C. Wang & S.L. Tung ● ●23 P. haoana Cheng & C. Wang ● ●24 P. xiangchengensis C. Wang & Tung ● ●25 P. ciliata Wall. ● 26 P. wuana C. Wang & S.L. Tung ● ●27 P. yuana C. Wang & S.L. Tung ● ●28 P. yatungensis C. Wang et S.L. Tung ● ●

General situation

Species

HybridsP. P. trinervistrinervis ×× P. P. simoniisimoniiP. P. adenopodaadenopoda ×× rotundifoliarotundifoliaP. P. cathayanacathayana ×× schneiderischneideriP. P. davidiandavidian×× rotundifoliarotundifoliaP. P. lancifolialancifolia ×× purdomiipurdomiiP. P. schneiderschneider ×× pseudoglaucapseudoglauca (P. (P. ×× xiangchengensisxiangchengensis))P. P. schneiderischneideri ×× purdomiipurdomii (P. (P. ×× yuanayuana))P. P. szechuanicaszechuanica ×× P. P. purdomiipurdomii ×× P. P. simoniisimoniiP. P. schneiderischneideri ××P. P. szechuanicaszechuanicaP. P. tibeticatibetica ×× P. P. purdomiipurdomiiP. P. purdomiipurdomii ×× P. P. yunnanensisyunnanensis

P. kangdingensis × P. pseudonglaucaP. pseudonglauca × P. fangianP. szechuanica × P. cathayanaP. cathayana × P. trinervis

P. wilsonii P. schneideri var. tibetica

P. wilsonii var. lasioclada P. kangdingensis

P. gonggaensis P. caspica

P. purdomii P. ciliate var. ciliate

P. pseudonglauca P. ciliate var. gyirongensis

P. yatungensis P. ciliate var. aurea

P. ciliata var. weixi P. wuana

P. haoana P. × xiangchengensis

P. yunnanensis P.× yuana

P. adenopoda P. szechuanica

P. rotundifolia P. cathayana

P. davidiana var.davidiana P. przewalskii

P. davidiana var. tomentella P. simonii

P. lasiocarpa P.trinervis var. trinervis

P. lasiocarpa var. logiamenta P.trinervis var.shimianica

P. lasiocarpa var. psiloclada P. fangian var. fanian

P. lasiocarpa var. yiliangensis P. fangian var. microphylla

P. glauca P. lancifolia

Distribution

There is a notable distributing hot spot –Kangding county. And the Daduhe River is the most important distributing area for the native poplar.

The vertical distribution of the poplars ranges from about 500 m to 4500 m above sea level (a.s.l). Generally, there are different species appearing with the altitude change along a valley.

A typical distribution pattern of poplar species along a A typical distribution pattern of poplar species along a river (or valley)river (or valley)

Adaptability

The species fall into 3 types of plant The species fall into 3 types of plant

flora: Chinaflora: China--Japan, ChinaJapan, China--Himalayas, Himalayas,

and approximate ancient tropical zone. and approximate ancient tropical zone.

They can adapt to a variety of They can adapt to a variety of

environmental conditions.environmental conditions.

Low maintain & hill type: P. adenopoda, P. lasiocarpaDry & hot valley type: P. yunnanensis, P. simonii, P. trinervis

Warm & humid canyon type: P. cathayana , P. szechuanica, P. pseudonglauca, etc.

Warm & semiarid plateau: P. yunnanensis, Butuo large-leaf poplar

High-cold plateau type: P. przewalskii, P. kangdingensis, P. schneider var. tibeticaMountainside type: P. davidian, P. rotundifolia

GrowthP. trinervis P. trinervis andand P. yunnanensis P. yunnanensis have an excellent have an excellent

growth in diameter and height of up to 3 cm and 3 growth in diameter and height of up to 3 cm and 3

m per year, respectively.m per year, respectively.

Even under unfavorable climatic conditions at high Even under unfavorable climatic conditions at high

altitudes (more than 3500 meters) and with a short altitudes (more than 3500 meters) and with a short

growth season, growth season, P. P. kangdingesiskangdingesis and and P. P. schneiderischneideri

var. var. tibeticatibetica stand out due to their remarkable stand out due to their remarkable

growth in diameter and height of up to 1.5 cm and growth in diameter and height of up to 1.5 cm and

1 m per year respectively.1 m per year respectively.

Research

Origin, dispersal and evolutionOrigin, dispersal and evolution

ClassificationClassification

Genetic diversityGenetic diversity

Genetic improvementGenetic improvement

Origin, dispersal, evolution

Southwest China is likely to be the cradle of Southwest China is likely to be the cradle of PopulusPopulus, especially for Tacamahaca., especially for Tacamahaca.The evolutional affiliation among the native The evolutional affiliation among the native poplars has not been identified clearly.poplars has not been identified clearly.A systemic study involving all the species A systemic study involving all the species on genetic and evolutional relationship will on genetic and evolutional relationship will help to resolve the scientific problems.help to resolve the scientific problems.

Scientific research

Classification

Some contradictions on Populus classification still exist. First, a gulf lies between slippers and clumpers.Second, there is a severe argument on some species’ taxonomic treatments.A new taxonomic system proposed by ChaoNeng classified the Populus in southwest China into 20 species and 22 varieties.

Scientific research

Genetic diversity of P. cathayana and P. yunnanensis was estimated by molecular markers, while the other species have not been involved.

Genetic diversity

Scientific research

Genetic improvement

Only a few works, such as selection breeding Only a few works, such as selection breeding

of of P. kangdingensis and hybridization

breeding of P. yunnanensis, were were

sporadically carried out in the past.sporadically carried out in the past.

The other species are almost blank.The other species are almost blank.

Scientific research

We have screened 58 superior trees derived We have screened 58 superior trees derived

from 14 species since 2007 by selection from 14 species since 2007 by selection

breeding, and the materials are being breeding, and the materials are being

cloned and evaluated.cloned and evaluated.

P. pseudoglauca P. yunnanensis P. trinervis

Poplar is a a main component of riparian ecosystem in the region, and it plays an important role on maintaining ecological balance of steams.

Application

P. pseudonglauca P. yunnanensis

It is grown extensively to provide wood, fuel It is grown extensively to provide wood, fuel and forage, and to protect the agricultural and forage, and to protect the agricultural fields, grazing lands, cities and villages. fields, grazing lands, cities and villages.

Application

P. schneideri var. tibetica

Poplar has been regarded as one of the pillars Poplar has been regarded as one of the pillars of forestry in of forestry in ButuoButuo, , ZhaojueZhaojue, , MeiguMeigu and and DaochengDaocheng counties, where the general counties, where the general planning has been done to direct the poplar planning has been done to direct the poplar development.development.

P. kangdingensisP. schneideri var. tibetica

P. P. kangdingensiskangdingensis, , P. P. schneiderischneideri var. var.

tibeticatibetica and and P. P. yunanensisyunanensis are widely are widely

cultured, and cultured, and P. xiangchengensisP. xiangchengensis and and P. P.

trinervistrinervis are grown in a small scale, while are grown in a small scale, while

the others are only sporadically planted the others are only sporadically planted

or have not any cultivation. or have not any cultivation.

Cultivation acreage

Conventionally, the local farmers Conventionally, the local farmers

usually cut large branches from adult usually cut large branches from adult

individuals as planting stocks. individuals as planting stocks.

Cultivation methods

P. kangdingensisP. kangdingensis

P. yunnanensis

In recent years, rooted stocks of 1In recent years, rooted stocks of 1-- or or

22--yearyear--old have been almost old have been almost

popularized on forestation projects popularized on forestation projects

organized by local Forestry Bureau. organized by local Forestry Bureau.

P. yunnanensis P. schneideri var. tibetica

The utilization of poplar is very The utilization of poplar is very traditional, and they are mainly grown for traditional, and they are mainly grown for constructconstruct--wood, firewood and forage wood, firewood and forage forests, as well as shelterbelts and forests, as well as shelterbelts and scenic forests. scenic forests. Since the poor economic and traffic Since the poor economic and traffic conditions, there is no industrial conditions, there is no industrial processing and utilization.processing and utilization.

Utilization

ConservationNo systemic conservation work has been done up to today.Extensive economic expansion, especially hydropower construction, has been bringing a severe damage to the resource.

Daduhe riverWashihe river

A gene pool was preliminarily built in Ya’anSichuan 2008. It contains about 950 genotypes from about 30 species, varieties and hybrids coming from Sichuan province.

The gene pool in Ya’an

Many important materials, especially in Tibet an Yunnan province, have not be enrolled in the pool.Along the way to construct this gene pool, there are still many difficulties to get over in the future.

For the poplars have great values on scientific For the poplars have great values on scientific

research and practical application, as well as research and practical application, as well as

have been facing serious threat, it is have been facing serious threat, it is

necessary and urgent to build a national necessary and urgent to build a national

protection system including inprotection system including in--situ, exsitu, ex--situ situ

and inand in--vitro conservation.vitro conservation.

Suggestions

Because extensive hydropower exploitation Because extensive hydropower exploitation

is the primary reason that caused poplar is the primary reason that caused poplar

resource rapid disappear in the southwest resource rapid disappear in the southwest

China, it is necessary to collect and conserve China, it is necessary to collect and conserve

the poplars distributing along a stream, the poplars distributing along a stream,

where hydropower station will be built in where hydropower station will be built in

the coming future, before the beginning of the coming future, before the beginning of

construction.construction.

Improved variety and planting technology

are the two major limiting factors to the

development of native poplar in the region,

so the studies on breeding and cultivation he studies on breeding and cultivation

should be given more support. should be given more support.

The classification research should also be The classification research should also be

strengthened strengthened

Conclusion

It is very urgent to conserve the genetic

resource of Populus, and we would like to

appeal to more people to pay attention to its

conservation and application for the

sustainable development of poplar culture.

Our worksResource collection and gene pool

construction

Classification based on morphological,

molecular and cell biology.

Genetic diversity

Selecting Breeding

Physiological ecology

Our team

Acknowledgment

This project was funded by Science and This project was funded by Science and

Technology Bureau of Sichuan Province, Technology Bureau of Sichuan Province,

China. We thanks Prof. Liu D.J., Liu Y.A., China. We thanks Prof. Liu D.J., Liu Y.A.,

Cheng X.B. for the help during field Cheng X.B. for the help during field

investigation, and Prof. He J.R. and Prof. Liu investigation, and Prof. He J.R. and Prof. Liu

J for help on sample identification. J for help on sample identification.

Thank you. Welcome to Sichuan

Forestry college, Sichuan Agricultural University Yaan 625014, Sichuan, China

wanxueq@yahoo.com, +86-138-8163-4583