CONE AND SEED CHARACTERISTICS OF PINUS DENSATA AND THEIR ADAPTIVE FITNESS IMPLICATIONS

doi:10.17521/cjpe.2007.0033

Abstract

Abstract:

Aims Pinus densata is an important forest species in the high mountains of the southeastern Tibetan Plateau. Previous investigations demonstrated that this pine originated through natural hybridization between P. yunnanensis and P. tabulaeformis. The mechanisms underlying this hybrid speciation and especially its adaptive evolution are poorly understood. Reproductive fitness plays a critical role in hybrid speciation; however, the fitness of P. densata in the high plateau environment has not been investigated.

Methods We investigated 13 cone and seed characters, related to reproductive potential of the species, from six representative populations distributed throughout its natural range. The 13 characters are cone length, number of scales per cone, number of fertile scales, cone scale density, fertile scale density, ratio of fertile scales, number of seeds per cone, seed length, length of seed wing, total seed length per cone, total length of seed wing per cone, seed productivity per cone and ovule abortion rate. Patterns of variation of these characters were analyzed using one-way ANOVA and correlated to geo-ecological factors of each population.

Important fingdings Characters, such as cone length, total number of scales in a cone and number of seeds per cone in P. densata were similar to that in P. tabulaeformis, P. yunnanensis and several other species of Pinus. The maximum mean value of seed productivity per cone was 74%. One-way ANOVA showed significant (p<0.01) differentiation in all 13 characters among the six populations. Correlation analysis between cone and seed characters and geo-ecological factors indicated that total number of cone scales, number of fertile scales, number of seeds per cone and ratio of fertile scales were negatively correlated with latitude and seed productivity was positively correlated with longitude and ecological gradient axes. All results suggested thatP. densata as a hybrid species is not inferior in reproductive fitness in the plateau environment. The patterns of geographic variations in cone and seed characters seem to be related to the genetic background and divergent ecological environments of the populations.

Key words: hybrid, reproductive characters, population differentiation, geographic variation, ecological adaptation

MAO Jian-Feng, LI Yue, LIU Yu-Jun, LIU Hao, WANG Xiao-Ru. CONE AND SEED CHARACTERISTICS OF PINUS DENSATA AND THEIR ADAPTIVE FITNESS IMPLICATIONS[J]. Chin J Plant Ecol, 2007, 31(2): 291-299.

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Figures/Tables 4

References 45

[1]	Arnold ML (1993). Iris nelsonii (Iridaceae): origin and genetic composition of a homoploid hybrid species. American Journal of Botany, 80,577-583. DOI URL PMID
[2]	Arnold ML, Hodges SA (1995). Are natural hybrids fit or unfit relative to their parents? Trends in Ecology and Evolution, 10,67-71. DOI URL PMID
[3]	Bazzaz FA (1991). Habitat selection in plants. American Naturalist, 137,116-130.
[4]	Bennett BD, Grace JB (1990). Shade tolerance and its effect on the segregation of two species of Louisiana Iris and their hybrids. American Journal of Botany, 77,100-107.
[5]	Chen YS (陈幼生) (2001). Pinus. In: National Forestry Center and Tree Seed Station of National Forestry Bureau(国家林业局国有林场和林木种苗工作总站) ed. Seeds of Woody Plants in China (中国木本植物种子). China Forestry Publishing House, Beijing, 47-66. (in Chinese)
[6]	Clausen J (1951). Stages in the Evolution of Plant Species. Cornell University Press, New York.
[7]	Cruzan MB, Arnold ML (1993). Ecological and genetic associations in an Iris hybrid zone. Evolution, 47,1432-1445. URL PMID
[8]	Cruzan MB, Arnold ML (1994). Assortative mating and natural selection in an Iris hybrid zone. Evolution, 48,1946-1958. URL PMID
[9]	Dobzhansky TH (1937). Genetics and the Origin of Species. Columbia University Press, New York.
[10]	Freeman DC, Graham JH, Byrd DW, McArthur ED, Turner WA (1995). Narrow hybrid zone between two subspecies of big sagebrush ( Artemisia tridentata: Asteraceae). Ⅲ. Developmental instability. American Journal of Botany, 82,1144-1152.
[11]	Fu LK, Li N, Mill RR (1999). Pinus. In: Wu ZY, Raven PH eds. Flora of China. Science Press, Beijing; Missouri Botanical Garden Press, St Louis, 11-25.
[12]	Givnish TJ (1981). Serotiny, geography and fire in the pine barrens of New Jersey. Evolution, 35,101-123.
[13]	Graham JH, Freeman DC, McArthur ED (1995). Narrow hybrid zone between two subspecies of big sagebrush ( Artemisia tridentata: Asteraceae). Ⅱ. Selection gradients and hybrid fitness. American Journal of Botany, 82,709-716.
[14]	Grant V (1966). Selection for vigor and fertility in the progeny of a highly sterile species hyrid in Gilia. Genetics, 53,757-775. URL PMID
[15]	Gross BL, Rieseberg LH (2005). The ecological genetics of homoploid hybrid speciation. Journal of Heredity, 96,241-252.
[16]	Gu WC (顾万春) (2004). Statistical Genetics (统计遗传学). Science Press, Beijing. (in Chinese)
[17]	Guan ZT (管中天) (1981). Fundamental features of the distribution of Coniferae in Sichuan. Acta Phytotaxonomica Sinica (植物分类学报), 19,393-407. (in Chinese with English abstract)
[18]	Harper JL (1977). Population Biology of Plants. Academic Press, London.
[19]	Heiser CB (1947). Hybridization between the sunflower species Helianthus annuus and H. petiolaris. Evolution, 1,249-262.
[20]	Isik K (1986). Altitudinal variation in Pinus brutia Ten.: seed and seedling characteristics. Silvae Genetica, 35,58-67.
[21]	Li B (李斌), Gu WC(顾万春), Lu BM (卢宝明) (2002). A study on phenotypic diversity of seeds and cones characteristics in Pinus bungeana. Biodiversity Science (生物多样性), 10,181-188. (in Chinese with English abstract)
[22]	Li Z, Pinson SRM, Paterson AH, Park WD, Stansel JW (1997). Genetics of hybrid sterility and hybrid breakdown in an intersubspecific rice ( Oryza sativa L.) population. Genetics, 145,1139-1148. URL PMID
[23]	Liu ZL, Zhang D, Hong DY, Wang XR (2003). Chromosomal localization of 5S and 18S-5.8S-25S ribosomal DNA sites in five Asian pines using fluorescence in situ hybridization. Theoretical and Applied Genetics, 106,198-204. URL PMID
[24]	Mirov NT (1967). The Genus Pinus. Ronald Press, New York.
[25]	Potts BM (1986). The population dynamics and regeneration of a hybrid zone between Eucalyptus risdonii and E. amygdalina. Australian Journal of Botany, 34,305-329.
[26]	Rehfeldt GE (1983). Adaptation of Pinus contorta populations to heterogeneous environments in northern Idaho. Candian Journal of Forest Research, 13,405-411.
[27]	Rieseberg LH (1991). Homoploid reticulate evolution in Helianthus (Asteraceae): evidence from ribosomal genes. American Journal of Botany, 78,1218-1237.
[28]	Rieseberg LH (1997). Hybrid origins of plant species. Annual Review of Ecology and Systematics, 28,359-389.
[29]	Rieseberg LH, Archer MA, Wayne RK (1999). Transgressive segregation, adaptation and speciation. Heredity, 83,363-372. URL PMID
[30]	Ruby JL (1967). The correspondence between genetic,morphological and climatic variation pattern in Scotch pine. Silvae Genetica, 16,50-56.
[31]	Song BH, Wang XQ, Wang XR, Ding KY, Hong DY (2003). Cytoplasmic composition in Pinus densata and population establishment of the diploid hybrid pine. Molecular Ecology, 12,2995-3001. URL PMID
[32]	Song BH, Wang XQ, Wang XR, Sun LJ, Hong DY, Peng PH (2002). Maternal lineages of Pinus densata, a diploid hybrid. Molecular Ecology, 11,1057-1063. URL PMID
[33]	Sun Yl (孙玉玲), Li QM (李庆梅), Xie ZQ (谢宗强) (2005). Fruiting characteristics of the endangered species Abies chensiensis. Acta Phytoecologica Sinica (植物生态学报), 29,251-257. (in Chinese with English abstract)
[34]	Wang XR (王晓茹), Shen XH (沈熙环) (1989). Studies on increasing seed production in seed orchards of Pinus tabulaeformis Carr. — an analysis of seed losses caused by aborted ovules and empty seeds. Journal of Beijing Forestry University (北京林业大学学报), 11,60-66. (in Chinese with English abstract)
[35]	Wang XR, Szmidt AE (1990). Evolutionary analysis of Pinus densata (Masters), a putative tertiary hybrid. 2. A study using species specific chloroplast DNA markers. Theoretical and Applied Genetics, 80,641-647. DOI URL PMID
[36]	Wang XR, Szmidt AE (1994). Hybridization and chloroplast DNA variation in a Pinus species complex from Asia. Evolution, 48,1020-1031. DOI URL PMID
[37]	Wang XR, Szmidt AE, Lewandowski A, Wang ZR (1990). Evolutionary analysis of Pinus densata Masters, a putative tertiary hybrid. 1. Allozyme variation. Theoretical and Applied Genetics, 80,635-640. DOI URL PMID
[38]	Wang XR, Szmidt AE, Savolainen O (2001). Genetic composition and diploid hybrid speciation of a high mountain pine, Pinus densata, native to the Tibetan Plateau. Genetics, 159,337-346.
[39]	Wells OO (1964). Geographic variation in ponderosa pine. Ⅱ. Correlations between progeny performance and characteristics of native habitats. Silvae Genetics, 13,126-164.
[40]	Wheeler NC, Guries RP (1982). Population structure, genic diversity, and morphological variation in Pinus contorta Dougl. Canadian Journal of Forest Research, 12,595-606.
[41]	Williams JH, Boecklen WJ, Howard DJ (2001). Reproductive processes in two oak ( Quercus) contact zones with different levels of hybridization. Heredity, 87,680-690. URL PMID
[42]	Wu ZL (吴中伦) (1956). The taxonomic revision and phytogeographical study of Chinese pines. Acta Phytotaxonomica Sinica (植物分类学报), 5,131-163. (in Chinese)
[43]	Xie ZQ (谢宗强), Chen WL (陈伟烈), Hu D (胡东), Zhu RG (朱日光) (1998). The fruiting characteristics of an endangered plant, Cathaya argrophylla and the impact of animals on fruits. Acta Phytoecologica Sinica (植物生态学报), 22,319-326. (in Chinese with English abstract)
[44]	Xu HC (徐化成) (1991). Geographical Variation and Seed Source Choice of Pinus tabulaeformis (油松地理变异和种源选择). China Forestry Publishing House, Beijing. (in Chinese)
[45]	Yu H, Ge S, Hong DY (2000). Allozyme diversity and population genetic structure of Pinus densata Master in northwestern Yunnan, China. Biochemical Genetics, 38,139-147. URL PMID

采集地 Populations	缩写 Abbreviation	纬度 Latitude	经度 Longitude	海拔(m) Elevation	生态梯度综合值 EGA	球果个数 No. of cones
云南迪庆州中甸县Zhangdian, Yunnan	ZD	27°48' N	99°42' E	2 900	10.04	29
西藏林芝县八一镇Bayi, Linzhi, Tibet	BY	29°41' N	94°21' E	2 900	9.23	51
西藏林芝县尼西乡Nixi, Linzhi, Tibet	NX	29°45' N	94°17' E	3 200	9.49	45
西藏波密县通麦镇Tongmai, Bomi, Tibet	TM	30°09' N	95°17' E	2 300	7.91	50
四川理县Lixian, Sichuan	LX	30°59' N	102°21' E	2 500	10.30	26
四川小金县Xiaojin, Sichuan	XJ	31°26' N	103°10' E	2 700	10.62	48

采集地 Populations	缩写 Abbreviation	纬度 Latitude	经度 Longitude	海拔(m) Elevation	生态梯度综合值 EGA	球果个数 No. of cones
云南迪庆州中甸县Zhangdian, Yunnan	ZD	27°48' N	99°42' E	2 900	10.04	29
西藏林芝县八一镇Bayi, Linzhi, Tibet	BY	29°41' N	94°21' E	2 900	9.23	51
西藏林芝县尼西乡Nixi, Linzhi, Tibet	NX	29°45' N	94°17' E	3 200	9.49	45
西藏波密县通麦镇Tongmai, Bomi, Tibet	TM	30°09' N	95°17' E	2 300	7.91	50
四川理县Lixian, Sichuan	LX	30°59' N	102°21' E	2 500	10.30	26
四川小金县Xiaojin, Sichuan	XJ	31°26' N	103°10' E	2 700	10.62	48

居群 Populations	球果长度 Cone length (cm)	可育种鳞数 Fertile scales	总种鳞数 Total No. of scales	总种子数 Total No. of seeds	种子长 Seed length (cm)	种翅长 Length of seed wing (cm)	可育种鳞率 Ratio of fertile scales (%)
中甸 ZD	5.09 (0.44)	48.55 (2.45)	131.45 (4.34)	76.90 (4.44)	0.54 (0.04)	1.87 (0.03)	36.86 (1.34)
八一 BY	6.54 (0.15)	36.34 (1.56)	120.68 (2.15)	54.52 (2.79)	0.59 (0.01)	2.26 (0.03)	30.12 (1.18)
尼西 NX	5.78 (0.08)	34.76 (1.54)	111.96 (2.12)	46.84 (3.18)	0.55 (0.00)	1.99 (0.03)	31.00 (1.17)
通麦 TM	5.37 (0.11)	31.36 (1.05)	112.09 (2.03)	41.02 (1.72)	0.55 (0.01)	1.95 (0.04)	28.16 (1.00)
理县 LX	4.45 (0.12)	26.50 (1.57)	102.46 (3.24)	42.50 (3.03)	0.55 (0.01)	1.67 (0.02)	25.57 (1.00)
小金 XJ	4.91 (0.11)	27.54 (1.15)	95.15 (2.01)	46.13 (2.18)	0.69 (0.00)	2.19 (0.01)	28.98 (1.00)
总体Total	5.47 (0.06)	33.82 (0.74)	111.77 (1.23)	50.24 (1.35)	0.58 (0.01)	2.03 (0.02)	30.00 (0.49)
居群 Populations	球果结种率 Seed productivity (%)	胚珠败育率 Ovule abortion rate (%)	可育种鳞密度 Fertile scale density (N·cm^-1)	总种鳞密度 Total scale density (N·cm^-1)	种子总长 Total seed length (cm)	种翅总长 Total length of seed wings (cm)
中甸 ZD	78.85 (1.90)	20.63 (2.02)	9.49 (0.37)	25.89 (0.64)	42.75 (5.26)	144.75 (9.58)
八一 BY	74.77 (2.13)	25.23 (2.13)	5.53 (0.20)	18.78 (0.45)	32.21 (1.76)	124.12 (6.65)
尼西 NX	67.02 (2.79)	32.98 (2.79)	6.01 (0.25)	19.01 (0.44)	25.90 (0.44)	92.52 (5.92)
通麦 TM	65.43 (2.05)	34.57 (1.67)	5.90 (0.21)	21.32 (0.62)	22.45 (0.99)	80.56 (4.06)
理县 LX	78.94 (1.60)	21.05 (2.42)	5.88 (0.24)	23.15 (0.66)	23.29 (1.52)	70.86 (5.14)
小金 XJ	83.06 (0.84)	16.94 (0.84)	5.68 (0.22)	19.63 (0.41)	31.89 (1.52)	101.42 (4.92)
总体Total	74.00 (0.93)	25.94 (0.94)	6.22 (0.12)	20.84 (0.25)	29.39 (0.96)	102.24 (2.86)

居群 Populations	球果长度 Cone length (cm)	可育种鳞数 Fertile scales	总种鳞数 Total No. of scales	总种子数 Total No. of seeds	种子长 Seed length (cm)	种翅长 Length of seed wing (cm)	可育种鳞率 Ratio of fertile scales (%)
中甸 ZD	5.09 (0.44)	48.55 (2.45)	131.45 (4.34)	76.90 (4.44)	0.54 (0.04)	1.87 (0.03)	36.86 (1.34)
八一 BY	6.54 (0.15)	36.34 (1.56)	120.68 (2.15)	54.52 (2.79)	0.59 (0.01)	2.26 (0.03)	30.12 (1.18)
尼西 NX	5.78 (0.08)	34.76 (1.54)	111.96 (2.12)	46.84 (3.18)	0.55 (0.00)	1.99 (0.03)	31.00 (1.17)
通麦 TM	5.37 (0.11)	31.36 (1.05)	112.09 (2.03)	41.02 (1.72)	0.55 (0.01)	1.95 (0.04)	28.16 (1.00)
理县 LX	4.45 (0.12)	26.50 (1.57)	102.46 (3.24)	42.50 (3.03)	0.55 (0.01)	1.67 (0.02)	25.57 (1.00)
小金 XJ	4.91 (0.11)	27.54 (1.15)	95.15 (2.01)	46.13 (2.18)	0.69 (0.00)	2.19 (0.01)	28.98 (1.00)
总体Total	5.47 (0.06)	33.82 (0.74)	111.77 (1.23)	50.24 (1.35)	0.58 (0.01)	2.03 (0.02)	30.00 (0.49)
居群 Populations	球果结种率 Seed productivity (%)	胚珠败育率 Ovule abortion rate (%)	可育种鳞密度 Fertile scale density (N·cm^-1)	总种鳞密度 Total scale density (N·cm^-1)	种子总长 Total seed length (cm)	种翅总长 Total length of seed wings (cm)
中甸 ZD	78.85 (1.90)	20.63 (2.02)	9.49 (0.37)	25.89 (0.64)	42.75 (5.26)	144.75 (9.58)
八一 BY	74.77 (2.13)	25.23 (2.13)	5.53 (0.20)	18.78 (0.45)	32.21 (1.76)	124.12 (6.65)
尼西 NX	67.02 (2.79)	32.98 (2.79)	6.01 (0.25)	19.01 (0.44)	25.90 (0.44)	92.52 (5.92)
通麦 TM	65.43 (2.05)	34.57 (1.67)	5.90 (0.21)	21.32 (0.62)	22.45 (0.99)	80.56 (4.06)
理县 LX	78.94 (1.60)	21.05 (2.42)	5.88 (0.24)	23.15 (0.66)	23.29 (1.52)	70.86 (5.14)
小金 XJ	83.06 (0.84)	16.94 (0.84)	5.68 (0.22)	19.63 (0.41)	31.89 (1.52)	101.42 (4.92)
总体Total	74.00 (0.93)	25.94 (0.94)	6.22 (0.12)	20.84 (0.25)	29.39 (0.96)	102.24 (2.86)

性状 Characters	均方(自由度) MS (df)		F值 F value	方差分量 Variance		方差分量百分比 Percentage of variance (%)
性状 Characters	居群间 Among populations	居群内 Within population	居群间 Among populations	居群间 Among populations	居群内 Within population	居群间 Among populations	居群内 Within population
球果长度 Cone length (cm)	21.05 (5)	0.59 (243)	35.84^**	105.26	142.74	42	58
可育种鳞数Fertile scales	14.95 (5)	0.71 (243)	20.97^**	74.75	173.25	30	70
总种鳞数 Total No. of scales	16.39 (5)	0.68 (243)	23.99^**	81.97	166.03	33	67
总种子数 Total No. of seeds	12.57 (5)	0.76 (243)	16.49^**	62.83	185.17	25	75
种子长 Seed length (cm)	13.67 (5)	0.74 (243)	18.49^**	68.36	179.64	28	72
种翅长 Length of seed wing (cm)	25.04 (5)	0.51 (243)	49.54^**	125.19	122.81	50	50
可育种鳞率 Ratio of fertile scales (%)	7.09 (5)	0.87 (243)	8.10^**	35.43	212.57	14	86
球果结种率Seed productivity (%)	10.26 (5)	0.81 (243)	12.68^**	51.32	196.68	21	79
胚珠败育率 Ovule abortion rate (%)	10.30 (5)	0.81 (243)	12.74^**	51.49	196.51	21	79
可育种鳞密度 Fertile scale density (N·cm^-1)	18.40 (5)	0.64 (243)	28.65^**	91.99	156.01	37	63
总种鳞密度 Total scale density (N·cm^-1)	15.57 (5)	0.70 (243)	22.24^**	77.85	170.15	31	69
种子总长 Total seed length (cm)	8.43 (5)	0.85 (243)	9.94^**	42.13	205.87	17	83
种翅总长 Total length of seed wings (cm)	12.57 (5)	0.76 (243)	16.50^**	62.87	185.13	25	75