Diaspore characteristics of 22 families, including 102 genera and 150 species (55 represented by seeds and 95 by fruits) from the Gurbantunggut Desert were analyzed for diaspore biological characteristics (mass, shape, color, and appendage type). The diaspore mass and shape were significantly different in phylogeny group (APG) and dispersal syndromes; vegetative periods significantly affected diaspore mass, but not diaspore shape; and ecotypes did not significantly affect diaspore mass and shape, but xerophyte species had larger diaspore mass than mesophyte species. Unique stepwise ANOVA results showed that variance in diaspore mass and shape among these 150 species was largely dependent upon phylogeny and dispersal syndromes. Therefore, it was suggested that phylogeny may constrain diaspore mass, and as dispersal syndromes may be related to phylogeny, they also constrained diaspore mass and shape. Diaspores of 85 species (56.67%) had appendages, including 26 with wings/bracts, 18 with pappus/hair, 14 with hooks/spines, 10 with awns, and 17 with other types of appendages. Different traits (mass, shape, color, appendage, and dispersal syndromes) of diaspore decided plants forming different adapted strategies in the desert. In summary, the diaspore characteristics were closely related with phylogeny, vegetative periods, dispersal syndromes, and ecotype, and these characteristics allowed the plants to adapt to extreme desert environments.
Heritable characteristics of seeds that contribute to seed and seedling survivorship under natural conditions are open to natural selection. Sexual reproduction can improve the success rate of breeding more than asexual reproduction for plants in the face of adversity, so in response to plant propagation, sexual reproduction is the focus of the study [
A comparative study based on a large sample will enable ecologists to distinguish the main ways plants adapt to evolution and identify the plants with fitness (or lack of fitness) showing the physiological characteristics of life history in specific habitats [
Information on seed dispersal of desert plants is crucial in order to understand adaptative strategies of plants in desert areas. Our aim in this study is to discuss (1) the relationship of biological characteristics with phylogeny group (APG), vegetative periods, dispersal syndromes, and ecotypes and (2) the relationship between biological characteristics and dispersal adaptation to the desert ecological environment. The study may utilize to further reveal the universal pattern of plant life history and reproductive strategies in this cold desert and ulteriorly understand the continuous mechanisms for desert vegetation, population-proliferation regime, weed invasion mechanisms, and biodiversity loss mechanisms. Therefore, it has a great significance in taxonomy, ecology, and evolutionary biology for studying other cold deserts.
The cold desert is well-known due to it being located in colder areas with and higher latitude; and it is a dry, cold area of land that receives almost no precipitation. When it does, it is usually in the form of snow or fog [
In this paper, 150 plant species were selected for the study and classified into 28 families and 102 genera, which accounted for 72.8% of species, 82.9% of genera, and 93.3% of family in this area. Among them, there was one gymnosperm (0.67%), 15 monocotyledon (10.00%), with dominant Poaceae (13 species, 8.67%), and 134 dicotyledon (89.33%), with dominant Amaranthaceae (38 species, 25.33%), Brassicaceae (20 species, 13.33%), and Asteraceae (14 species, 9.33%). They were divided into 10 APG II taxonomic phylogeny groups as follows [
The species, APG II taxonomic phylogeny group, family, vegetative period, metrical object, diaspore characteristics (length, width, height, shape (variance), color, appendages), first dispersal phase (dispersal syndrome), second dispersal phase, and ecotype of 150 species in the Gurbantunggut Desert, northwest China.
APG II taxonomic phylogeny group | Family | Species | Vegetative period | Metrical object | Mass of 100 seeds |
Length, width, and height |
Diaspore shape variance | Diaspore color | Appendages | First dispersal phase (dispersal syndromes) | Second dispersal phase | Ecotype |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Coniferopsida | Ephedraceae |
|
S | Cone |
|
|
0.114 | Light brown | Bract | Anemochory | Ant | Xerophyte |
|
||||||||||||
Monocots | Liliaceae |
|
PH | Seed |
|
|
0.052 | Brown | Wing | Anemochory | Ant | Xerophyte |
Iridaceae |
|
PH | Seed |
|
|
0.053 | Reddish brown | None | Barochory | Ant | Mesophyte | |
|
||||||||||||
Commelinids | Poaceae |
|
PH | Seed |
|
|
0.157 | Brown | Hair | Zoochory | Ant | Xerophyte |
|
AH | Caryopsis |
|
|
0.150 | Brownish green | Awn | Zoochory | — | Xerophyte | ||
|
PH | Caryopsis |
|
|
0.167 | Yellowish green | Awn | Zoochory | — | Xerophyte | ||
|
AH | Caryopsis |
|
|
0.130 | Pale yellow | Awn | Zoochory | Ant | Mesophyte | ||
|
AE | Seed |
|
|
0.028 | Reddish brown | None | Anemochory | — | Mesophyte | ||
|
AE | Caryopsis |
|
|
0.176 | Yellowish green | Awn | Zoochory | Ant | Mesophyte | ||
|
AE | Caryopsis |
|
|
0.184 | Yellowish green | Awn | Zoochory | Ant | Xerophyte | ||
|
PH | Caryopsis |
|
|
0.206 | Pale yellow | Awn | Zoochory | Ant | Mesophyte | ||
|
PH | Caryopsis |
|
|
0.199 | Light green | Awn | Zoochory | Ant | Xerophyte | ||
|
PH | Caryopsis |
|
|
0.156 | Pale yellow | Awn | Zoochory | Ant | Mesophyte | ||
|
PH | Caryopsis |
|
|
0.071 | Pale yellow | Hair | Zoochory | Ant | Mesophyte | ||
|
PH | Caryopsis |
|
|
0.197 | Pale yellow | Awn | Zoochory | Ant | Mesophyte | ||
|
PH | Caryopsis |
|
|
0.205 | Yellowish brown | Awn | Zoochory | Ant | Mesophyte | ||
|
||||||||||||
Eudicots | Papaveraceae |
|
PH | Seed |
|
|
0.086 | Black | Placenta | Barochory | — | Xerophyte |
|
BPH | Seed |
|
|
0.065 | Black | None | Autochory | — | Xerophyte | ||
|
AE | Seed |
|
|
0.045 | Dark brown | Wart | Barochory | — | Xerophyte | ||
Ranunculaceae |
|
AE | Achenecetum |
|
|
0.018 | Black | Beak/spine | Zoochory | — | Mesophyte | |
|
SS | Achene |
|
|
0.126 | Brown | Pappus | Anemochory | — | Mesophyte | ||
|
||||||||||||
Core eudicots | Caryophyllaceae |
|
PH | Seed |
|
|
0.048 | Black | Wart | Barochory | — | Mesophyte |
Amaranthaceae |
|
AH | Seed |
|
|
0.108 | White | None | Barochory | Ant | Xerophyte | |
|
SS | Utricle |
|
|
0.104 | Dark reddish brown | Bract | Anemochory | — | Mesophyte | ||
|
AH | Utricle |
|
|
0.150 | Light yellowish brown | Bract | Anemochory | Ant | Mesophyte | ||
|
AH | Utricle |
|
|
0.168 | Yellowish brown | Bract | Anemochory | Ant | Mesophyte | ||
|
AH | Utricle |
|
|
0.150 | Light yellowish brown | Spine | Zoochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.040 | Yellowish brown | Hook/spine | Zoochory | — | Xerophyte | ||
|
SS | Utricle |
|
|
0.083 | Yellowish brown | Hair | Anemochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.364 | Dark green/pale yellow | Spine | Zoochory | Ant | Mesophyte | ||
|
S | Utricle |
|
|
0.179 | Brown | Hair | Anemochory | Ant | Mesophyte | ||
|
S/SS | Utricle |
|
|
0.076 | Brown | Hair | Anemochory | Ant | Mesophyte | ||
|
AH | Seed |
|
|
0.065 | Black | None | Barochory | Ant | Mesophyte | ||
|
AH | Seed |
|
|
0.037 | Black | None | Barochory | Ant | Mesophyte | ||
|
AH | Seed |
|
|
0.074 | Black | None | Barochory | Ant | Mesophyte | ||
|
AH | Utricle |
|
|
0.143 | Yellowish green | Beak | Zoochory | Ant | Mesophyte | ||
|
AH | Seed |
|
|
0.095 | Dark brown | Bract | Anemochory | Ant | Mesophyte | ||
|
AH | Seed |
|
|
0.088 | Yellowish brown | Bract | Anemochory | Ant | Mesophyte | ||
|
S | Utricle |
|
|
0.046 | Brown | None | Anemochory | — | Mesophyte | ||
|
SA | Utricle |
|
|
0.172 | Yellowish brown | Bract | Anemochory | Ant | Mesophyte | ||
|
SA | Utricle |
|
|
0.147 | Light yellowish brown | Bract | Anemochory | Ant | Mesophyte | ||
|
AH | Utricle |
|
|
0.083 | Pale yellow | Bract | Zoochory | — | Mesophyte | ||
|
SS | Utricle |
|
|
0.032 | Light yellowish brown | None | Anemochory | — | Mesophyte | ||
|
SS | Utricle |
|
|
0.081 | Light yellowish brown | None | Anemochory | — | Mesophyte | ||
|
SS | Utricle |
|
|
0.047 | Light yellowish brown | None | Anemochory | — | Mesophyte | ||
|
AH | Utricle |
|
|
0.037 | Dark brown | Hair | Anemochory | Ant | Mesophyte | ||
|
AH | Utricle |
|
|
0.104 | Pale yellow | Bract | Anemochory | Ant | Mesophyte | ||
|
AH | Utricle |
|
|
0.049 | Dark brown | None | Anemochory | — | Xerophyte | ||
|
AH | Utricle |
|
|
0.072 | Yellowish brown | Bract | Anemochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.182 | Reddish brown | Bract | Anemochory | — | Xerophyte | ||
|
AH | Utricle |
|
|
0.139 | Yellowish brown | Bract | Anemochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.115 | Yellowish brown | Bract | Anemochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.129 | Brown | Bract | Anemochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.117 | Yellowish brown | Bract | Anemochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.020 | Dark brown | None | Barochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.029 | Black | None | Barochory | Ant | Xerophyte | ||
|
AH | Utricle |
|
|
0.047 | Yellowish brown |
None | Barochory | Ant | Xerophyte | ||
|
SS | Utricle |
|
|
0.003 | Black/yellowish brown | None | Barochory | Ant | Xerophyte | ||
|
SS | Utricle |
|
|
0.029 | Reddish brown | Perianth | Anemochory | Ant | Mesophyte | ||
|
AH | Utricle |
|
|
0.034 | Black | None | Barochory | Ant | Mesophyte | ||
Polygonaceae |
|
S | Achene |
|
|
0.058 | Brown | Perianth | Anemochory | Ant | Xerophyte | |
|
S | Achene |
|
|
0.045 | Brown | Hook/spine | Zoochory | — | Mesophyte | ||
|
SS | Achene |
|
|
0.005 | Yellowish brown | Hook/spine | Zoochory | — | Xerophyte | ||
|
S | Achene |
|
|
0.087 | Yellowish brown | Wing | Zoochory | — | Xerophyte | ||
|
PH | Achene |
|
|
0.018 | Yellowish brown | Bract | Anemochory | Ant | Mesophyte | ||
Tamaricaceae |
|
SS | Capsule |
|
|
0.078 | Dark brown | Hair | Anemochory | Ant | Mesophyte | |
Plumbaginaceae |
|
PH | Utricle |
|
|
0.051 | Light brown | Bract | Anemochory | Ant | Mesophyte | |
|
PH | Utricle |
|
|
0.093 | Dark brown | Bract | Anemochory | Ant | Mesophyte | ||
|
PH | Utricle |
|
|
0.064 | Light brown | Bract | Anemochory | Ant | Mesophyte | ||
|
SS | Utricle |
|
|
0.109 | Light brown | Bract | Anemochory | Ant | Mesophyte | ||
|
||||||||||||
Rosids | Geraniaceae |
|
AE | Capsule |
|
|
0.154 | Brown | Pappus/beak | Anemochory | Ant | Xerophyte |
|
||||||||||||
Eurosids I | Fabaceae |
|
SS | Pod |
|
|
0.078 | Brown | None | Autochory | Ant | Xerophyte |
|
S/SS | Pod |
|
|
0.130 | Nut-brown | None | Barochory | Ant | Xerophyte | ||
|
SS | Pod |
|
|
0.091 | Light yellowish brown | Awn, papery calyx | Anemochory | Ant | Mesophyte | ||
|
PH | Pod |
|
|
0.091 | Brown | None | Autochory | Ant | Xerophyte | ||
|
PH | Seed |
|
|
0.038 | Brown | None | Autochory | Ant | Mesophyte | ||
|
PH | Seed |
|
|
0.039 | Light brown | None | Barochory | — | Xerophyte | ||
|
AE | Seed |
|
|
0.105 | Yellowish green | None | Autochory | Ant | Xerophyte | ||
|
AE | Seed |
|
|
0.107 | Yellowish green | None | Autochory | Ant | Xerophyte | ||
Zygophyllaceae |
|
S | Berry |
|
|
0.059 | Dark reddish brown | None | Zoochory | Ant | Xerophyte | |
|
S | Berry |
|
|
0.055 | Dark reddish brown | None | Zoochory | Ant | Xerophyte | ||
|
PH | Seed |
|
|
0.096 | Dark brown | None | Barochory | Ant | Mesophyte | ||
|
PH | Seed |
|
|
0.123 | Brown | Balloon | Barochory | Ant | Xerophyte | ||
|
PH | Seed |
|
|
0.140 | Brown | Wart | Barochory | Ant | Xerophyte | ||
|
S | Capsule |
|
|
0.051 | Pale yellow | Wing | Anemochory | Ant | Xerophyte | ||
Rosaceae |
|
PH | Achenecetum |
|
|
0.044 | Green | Hook/spine | Zoochory | Ant | Xerophyte | |
Cannabaceae |
|
AH | Capsule |
|
|
0.036 | Grey | None | Barochory | — | Mesophyte | |
|
||||||||||||
Eurosids II | Brassicaceae |
|
AE | Seed |
|
|
0.107 | Yellow | None | Ombro-hydrochory | — | Mesophyte |
|
AE | Seed |
|
|
0.111 | Yellow | None | Ombro-hydrochory | — | Xerophyte | ||
|
AH | Seed |
|
|
0.062 | Yellowish brown | None | Ombro-hydrochory | — | Xerophyte | ||
|
AH | Seed |
|
|
0.061 | Yellowish brown | None | Ombro-hydrochory | — | Mesophyte | ||
|
PH | Seed |
|
|
0.068 | Reddish brown | None | Ombro-hydrochory | Ant | Mesophyte | ||
|
PH | Seed |
|
|
0.070 | Reddish brown | None | Ombro-hydrochory | Ant | Xerophyte | ||
|
AH | Seed |
|
|
0.081 | Light reddish brown | None | Ombro-hydrochory | Ant | Xerophyte | ||
|
BPH | Seed |
|
|
0.091 | Brown | None | Ombro-hydrochory | Ant | Xerophyte | ||
|
AE | Silicle |
|
|
0.066 | Brownish green/brown | Beak | Zoochory | Ant | Xerophyte | ||
|
BH | Silicle |
|
|
0.129 | Yellowish brown | Wing | Barochory | Ant | Mesophyte | ||
|
AE | Silicle |
|
|
0.095 | Yellowish brown | Wing | Barochory | Ant | Mesophyte | ||
|
ABH | Seed |
|
|
0.074 | Reddish brown | None | Ombro-hydrochory | Ant | Mesophyte | ||
|
PH | Seed |
|
|
0.106 | Reddish brown | None | Ombro-hydrochory | — | Mesophyte | ||
|
PH | Seed |
|
|
0.074 | Reddish brown | None | Ombro-hydrochory | — | Mesophyte | ||
|
ABE | Seed |
|
|
0.102 | Yellowish brown | None | Ombro-hydrochory | Ant | Mesophyte | ||
|
BE | Seed |
|
|
0.080 | Light yellowish brown | None | Barochory | Ant | Mesophyte | ||
|
ABE | Seed |
|
|
0.117 | Yellowish brown | None | Ombro-hydrochory | — | Mesophyte | ||
|
BH | Seed |
|
|
0.103 | Orange | None | Ombro-hydrochory | — | Xerophyte | ||
|
AE | Seed |
|
|
0.086 | Light yellowish brown | None | Ombro-hydrochory | — | Mesophyte | ||
|
AE | Seed |
|
|
0.070 | Dark brown | None | Barochory | Ant | Mesophyte | ||
Malvaceae |
|
AH | Seed |
|
|
0.054 | Dark brown | Hair | Barochory | Ant | Mesophyte | |
|
PH | Schizocarp |
|
|
0.062 | Light brown | Hair | Barochory | Ant | Xerophyte | ||
|
BH | Schizocarp |
|
|
0.111 | Light brown | Hair | Barochory | Ant | Xerophyte | ||
|
AH | Seed |
|
|
0.028 | Black | Wart | Barochory | Ant | Xerophyte | ||
|
||||||||||||
Euasterids I | Scrophulariaceae |
|
PH | Seed |
|
|
0.028 | Black | None | Barochory | — | Mesophyte |
|
AH | Seed |
|
|
0.111 | Dark brown | None | Barochory | — | Mesophyte | ||
|
AE | Seed |
|
|
0.081 | Brown | None | Barochory | Ant | Mesophyte | ||
Solanaceae |
|
SS | Seed |
|
|
0.065 | Black | None | Barochory | — | Xerophyte | |
|
BH | Seed |
|
|
0.057 | Yellowish brown | None | Barochory | — | Xerophyte | ||
Boraginaceae |
|
AE | Nutlet |
|
|
0.052 | Brown | Hook/spine | Zoochory | — | Xerophyte | |
|
PH | Schizocarp |
|
|
0.049 | Brownish green | Wart | Barochory | Ant | Xerophyte | ||
|
ABE | Nutlet |
|
|
0.021 | Dark brown | Spine | Zoochory | Ant | Xerophyte | ||
|
AE | Nutlet |
|
|
0.016 | Light yellowish brown | Spine | Zoochory | Ant | Xerophyte | ||
|
AH | Nutlet |
|
|
0.015 | Brown | Spine | Zoochory | Ant | Xerophyte | ||
|
PH | Nutlet |
|
|
0.078 | Yellowish brown | Spine | Zoochory | Ant | Mesophyte | ||
Lamiaceae |
|
PH | Nutlet |
|
|
0.023 | Dark brown | Wart | Barochory | Ant | Xerophyte | |
|
PH | Nutlet |
|
|
0.086 | Light brown | None | Barochory | Ant | Mesophyte | ||
|
PH | Nutlet |
|
|
0.066 | Dark brown | Wart | Barochory | Ant | Mesophyte | ||
|
PH | Nutlet |
|
|
0.087 | Dark brown | None | Barochory | Ant | Mesophyte | ||
|
PH | Nutlet |
|
|
0.055 | Black | None | Barochory | Ant | Mesophyte | ||
Plantaginaceae |
|
AE | Seed |
|
|
0.129 | Yellowish brown | None | Ombro-hydrochory | Ant | Mesophyte | |
|
PH | Seed |
|
|
0.080 | Yellowish brown | None | Ombro-hydrochory | Ant | Xerophyte | ||
|
PH | Seed |
|
|
0.105 | Yellowish brown | None | Ombro-hydrochory | Ant | Xerophyte | ||
|
AE | Seed |
|
|
0.129 | Dark brown | None | Ombro-hydrochory | Ant | Xerophyte | ||
Convolvulaceae |
|
AH | Seed |
|
|
0.031 | Light brown | None | Barochory | Ant | Mesophyte | |
Rubiaceae |
|
PH | Seed |
|
|
0.041 | Dark brown | Wart | Barochory | Ant | Xerophyte | |
|
||||||||||||
Euasterids II | Campanulaceae |
|
PH | Seed |
|
|
0.074 | Light brown | None | Barochory | Ant | Mesophyte |
Asteraceae |
|
BH | Achene |
|
|
0.117 | Brown | Pappus | Anemochory | Ant | Mesophyte | |
|
BH | Achene |
|
|
0.107 | Brown | Pappus | Anemochory | Ant | Mesophyte | ||
|
AH | Achene |
|
|
0.119 | Light brown | None | Anemochory | Ant | Mesophyte | ||
|
SS | Achenecetum |
|
|
0.115 | Brown | None | Anemochory | Ant | Mesophyte | ||
|
BH | Achene |
|
|
0.111 | Pale yellow | Pappus | Anemochory | — | Xerophyte | ||
|
BPH | Achenecetum |
|
|
0.053 | Pale yellow | Hook/spine | Zoochory | Ant | Xerophyte | ||
|
PH | Achene |
|
|
0.127 | Yellowish brown | Pappus | Anemochory | Ant | Mesophyte | ||
|
PH | Achene |
|
|
0.093 | Greyish black | Hook/spine | Zoochory | Ant | Mesophyte | ||
|
AE | Achene |
|
|
0.116 | Light yellowish brown | Pappus/beak | Anemochory | Ant | Mesophyte | ||
|
AE | Achene |
|
|
0.111 | Brown | Hook/spine | Zoochory | Ant | Xerophyte | ||
|
AH | Achene |
|
|
0.116 | Dark brown | None | Anemochory | — | Mesophyte | ||
|
BH | Achene |
|
|
0.090 | Grey/greyish black | None | Barochory | Ant | Mesophyte | ||
|
PH | Achene |
|
|
0.123 | Greyish white | Pappus | Anemochory | Ant | Mesophyte | ||
|
AH | Achene |
|
|
0.040 | Yellowish green/green | Beak/hook/spine | Zoochory | — | Mesophyte | ||
Apiaceae |
|
BH | Schizocarp |
|
|
0.071 | Light yellowish brown | None | Barochory | — | Mesophyte | |
|
PH | Schizocarp |
|
|
0.130 | Pale yellow | None | Barochory | Ant | Xerophyte |
Notes: AH: annuals; ABH: annuals/biennials; BH: biennials; BPH: biennials/perennials; PH: perennials; S: shrubs; SS: semishrubs; SA: small arbor; AE: annuals ephemerals; ABE: annuals/biennials ephemerals; BE: biennial ephemerals.
Plant types with both short and long vegetative periods were evolved in this area [
Ecotypes were divided into 2 categories: xerophyte (67 species, 44.67%) and mesophyte (83 species, 55.33%) (Table
Metrical objects of 150 species could be divided into seeds (55 species) and fruits (95 species), which could be further divided into various types. Mass: With reference to Thompson’s method [ Shape: according to Thompson et al.’s methods [ Color: combining observation and [ Appendage: We observed and recorded the appendage features, such as wing/bract, pappus/hair, hook/spine, awn, or other kinds of appendages (such as style/perianth/beak/warts/placenta, etc.).
Because seed dispersal was divided into two phases. (1) Phase I dispersal represents the movement of the seeds from the parent plant to a surface, each of 150 study species were assigned to one of five dispersal syndromes in their primal dispersal phase, on the basis of data from field collections, observing seed ornamentation and appendages and descriptions from published flora [
SPSS 15.0 was used for calculating the mean and the standard error of data. The ANOVA method (SPSS 15.0) was applied to analyze the significant difference between the diaspore mass (weight)/shape in different APG, vegetative periods, ecotypes, and dispersal syndromes. To examine differences in diaspore mass and shape among vegetative periods and taxonomic class rank, we used the Kruskal-Wallis test (
The species of Core eudiocot were the most abundant in all groups of APG II (Figure
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore mass of 150 species grouped by different APG II taxonomic phylogeny group. Because Coniferopsida and Rosids are only one species, they do not compare with others.
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore mass of 150 species grouped by different vegetative periods. Because annual-biennial (ABH) species is only one species, it does not compare with others. AH = annuals; ABH = annuals/biennials; BH = biennials; BPH = biennials/perennials; PH = perennials; S = shrubs; SS = semishrubs; SA = small arbor; AE = annuals ephemerals; ABE = annuals/biennials ephemerals; BE = biennial ephemerals.
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore mass of 150 species grouped by different dispersal syndromes.
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore mass of 150 species grouped by different ecotypes
The diaspore mean shape variance showed differences in APG II group (
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore shape (variance) of 150 species grouped by different APG II taxonomic phylogeny group. Because Coniferopsida and Rosids are only one species, they do not compare with others.
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore shape (variance) of 150 species grouped by different vegetative periods. Because annual-biennial (ABH) species is only one species, it does not compare with others. AH = annuals; ABH = annuals/biennials; BH = biennials; BPH = biennials/perennials; PH = perennials; S = shrubs; SS = semishrubs; SA = small arbor; AE = annuals ephemerals; ABE = annuals/biennials ephemerals; BE = biennial ephemerals.
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore shape (variance) of 150 species grouped by different dispersal syndromes.
Box plots showing mean (+), median (—), quartiles, and outliers (-) of diaspore shape (variance) of 150 species grouped by different ecotypes.
Frequency distribution of diaspore geometric shape. (1) Spheroideus, nearly-spheroideus; (2) elipsoid, broad-elipsoid, narrow-ellipsoid, ovoid, elongated-ovoid, obovoid, elongated-obovoid, subulate-ovoid, cylindrical-obovoid, spherical, spherical-ovoid; (3) lenticular, planular-ovoid, oblate-disc; (4) cylindrical, conical; (5) spindly, lanceolate, needle, Linearis; (6) reni; (7) arcuatus, curved; (8) trigonous, triqueter; (9) fan, rhombus.
The the source of variance is following by Mazer’s method [
Multiway tests of between-subjects effects.
Source | Seed mass | Seed shape | |||||
---|---|---|---|---|---|---|---|
df |
|
Sig. |
|
|
Sig. |
| |
Model | 20 | 5.833 | 0.000 | 0.481 | 2.725 | 0.000 | 0.302 |
APG | 7 | 5.856 | 0.000 | 0.169 | 3.185 | 0.004 | 0.125 |
Vegetative period | 8 | 2.152 | 0.036 | 0.071 | 1.223 | 0.291 | 0.053 |
Dispersal syndromes | 4 | 9.733 | 0.000 | 0.160 | 1.748 | 0.143 | 0.040 |
Ecotype | 1 | 0.248 | 0.619 | 0.001 | 0.313 | 0.577 | 0.003 |
|
|||||||
|
|||||||
Model | 13 | 4.654 | 0.000 | 0.309 | 2.168 | 0.014 | 0.173 |
Vegetative period | 8 | 2.853 | 0.006 | 0.117 | 1.509 | 0.160 | 0.073 |
Dispersal syndromes | 4 | 7.650 | 0.000 | 0.157 | 4.706 | 0.001 | 0.115 |
Ecotype | 1 | 1.490 | 0.224 | 0.008 | 0.584 | 0.446 | 0.003 |
|
|||||||
|
|||||||
Model | 12 | 7.974 | 0.000 | 0.415 | 3.686 | 0.000 | 0.247 |
APG | 7 | 7.094 | 0.000 | 0.215 | 3.782 | 0.001 | 0.149 |
Dispersal syndromes | 4 | 11.135 | 0.000 | 0.193 | 1.296 | 0.275 | 0.029 |
Ecotype | 1 | 0.432 | 0.512 | 0.002 | 0.390 | 0.533 | 0.003 |
|
|||||||
|
|||||||
Model | 16 | 3.829 | 0.000 | 0.320 | 2.902 | 0.000 | 0.263 |
APG | 7 | 4.444 | 0.000 | 0.163 | 5.068 | 0.000 | 0.202 |
Vegetative period | 8 | 2.474 | 0.016 | 0.103 | 1.002 | 0.438 | 0.045 |
Ecotype | 1 | 0.944 | 0.333 | 0.005 | 0.255 | 0.614 | 0.003 |
|
|||||||
|
|||||||
Model | 19 | 6.164 | 0.000 | 0.480 | 2.867 | 0.000 | 0.300 |
APG | 7 | 6.103 | 0.000 | 0.175 | 3.322 | 0.003 | 0.127 |
Vegetative period | 8 | 2.184 | 0.033 | 0.072 | 1.246 | 0.278 | 0.056 |
Dispersal syndromes | 4 | 10.030 | 0.000 | 0.164 | 1.745 | 0.144 | 0.037 |
According to comparison and observation, the diaspore color of 150 species could be divided into the following eight groups (Figure
Frequency distribution of diaspore color. (1) Light brown, brown, dark brown, nut-brown; (2) light reddish brown, reddish brown, dark reddish brown; (3) light yellowish brown, yellowish brown, dark yellowish brown; (4) pale yellow, yellow, orange, reddish yellow; (5) light green, green, dark green, brownish green, yellowish green; (6) white; (7) grey, greyish white, greyish black; (8) black.
Of the 150 species examined, 85 species (56.67%) had typical appendages, in which (1) 26 species (17.33%) had wings or bracts, which effectively spread with the wind; (2) 18 species (12.00%) had pappus or hairs, which effectively spread with the wind or stuck on animals; (3) 14 species (9.33%) had hooks or spines, which effectively hook on animals; (4) 10 species (6.67%) had awns, which effectively hang on animals or insert into the soil cracks for colonization; and (5) 17 species (11.33%) had other appendages, including style, perianth, beak, warts, placenta, and so forth, separately helping in different ways of dispersal (Table
Diaspore mass might be the result of both selective pressures over a long-term ecological process and the constraints over the long-standing evolutionary history of the taxonomic group. Phylogenetic effects on life history traits have been interpreted as “phylogenetic constraints,” defined as “properties shared by the members of a monophyletic group by virtue of their common ancestry, which limits the response of these taxon to directional selection” [
Vegetative periods of plants have a close relationship with adaptation to interference [
Diaspore mass and shape are also related to vegetation dynamics [
Diaspore mass and shape showed significant differences among dispersal syndromes, which indicated that both of them were key factors in determining the dispersal syndrome. Moles et al. [
This phylogenetic pattern of diaspore mass was previously shown in different floras [
Plants growing in the Gurbantunggut Desert developed relevant diaspore morphology characteristics and dispersal syndromes adaptative to the desert environment in the long-term evolution. The Gurbantunggut Desert had a typical arid climate, including deeply buried groundwater and lack of surface runoff; most survivors in this environment were xerophyte plants [
There was a certain proportion of salt desert and salinity wasteland in Gurbantunggut Desert peripheral areas especially on the southern edge, where distributing a variety of typical halophytes or wide adaptable plants [
Mesophyte was also an important part of the flora and a majority of them were weeds. Their diaspores were small, and light mass, they effectively improved the dispersal range and effective reproductive rate, such as
On the surface, the brown-color which was close to the sand color could help them to avoid been eaten by ants. However, it was found that the diaspore color and ant dispersal had no significant relationship (
In general, the diaspore characteristics were closely related to phylogeny, vegetative periods, dispersal syndromes and ecotype, and these characteristics allowed the plants to adapt extreme desert environments. Diaspore characteristics of plants in this area are influenced by natural selection forces. This study has provided new insights into diaspore characteristics and their ecological adaptation in this cold desert. However, there are still many unanswered questions concerning key aspects of the dispersal traits. These are key research questions arising from this study, and important ones that will need to be addressed in the future.
The authors declare that there is no conflict of interests regarding the publication of this paper.
Funds for this study were provided by the National Basic Research Priorities Program of China (2012FY111500), West Light Foundation of The Chinese Academy of Sciences (XBBS201303), and the National Natural Science Foundation (31100399) of China.