共生真菌对兰科植物种间杂交后代种子萌发的效应

doi:10.17521/cjpe.2019.0048

摘要/Abstract

摘要：

石斛属(Dendrobium)植物在种子共生萌发过程中与真菌有着较为专一的共生关系, 为探讨这种共生关系在种间杂交后代上的进化和适应, 深入理解兰科植物和真菌共生关系的形成机制, 该研究利用能有效促进铁皮石斛(Dendrobium officinale)和齿瓣石斛(D. devonianum)种子萌发形成幼苗, 并具有较强专一性的胶膜菌属(Tulasnella)真菌SSCDO-5和瘤菌根菌属(Epulorhiza)真菌FDd1, 开展真菌对铁皮石斛和D. tortile种间杂交种子萌发效应的研究。结果表明, 在真菌与种子共生培养68天时, SSCDO-5菌株和FDd1菌株都能有效地促进杂交种子形成原球茎和幼苗, 两个接菌处理之间无显著差异, 来源于铁皮石斛的SSCDO-5菌株不但没有表现出优势, 反而在杂交石斛幼苗形成率上低于来源于齿瓣石斛的FDd1菌株(SSCDO-5: (22.13 ± 6.62)%; FDd1: (29.53 ± 5.51)%); SSCDO-5菌株和铁皮石斛在幼苗形成和发育阶段的共生专一性并没有在杂交后代上得到遗传或表现, 或者说是杂交打破了这种专一性的共生关系, 使得杂交后代能够和不同的真菌建立新的共生关系。该结果不支持关于共生真菌专一性是石斛属植物杂交后代形成的重要限制因素的假设, 推测石斛属植物在幼苗分化和发育阶段与真菌这种专一性的共生关系是在适应特定生态环境的过程中形成和建立的。

关键词: 共生专一性, 菌根真菌, 兰科植物, 石斛属, 杂交物种形成, 种子共生萌发

Abstract:

AimsPrevious studies have shown that Dendrobium plants form a specific symbiotic relationship with fungi at differentiation stages during natural seed germination. In order to explore the evolution and adaptation of this symbiotic relationship in interspecific hybrid progenies, this study was to understand whether the strong specificity with symbiotic fungi during seedling formation and differentiation was also an important factor limiting the formation of hybrid progenies in Dendrobium, and the relationship between hybrid progenies of orchids and symbiotic fungi during seed germination stage.
MethodsThe effects of fungi on germination of interspecific hybrid seeds of D. officinale and D. tortile were studied using the highly specific fungi strains Tulasnella SSCDO-5 and Epulorhiza FDd1, which can effectively promote seed germination and seedling formation in D. officinale and D. devonianum, respectively.
Important findings The results showed that both SSCDO-5 and FDd1 strains could effectively promote the protocorm and seedling formation of hybrid seeds after 68 days incubation with no significant difference. The SSCDO-5 strain from D. officinale did not show any advantages, and the seedling formation rate of hybrid was lower than that of FDd1 strain from D. devonianum. The seedling formation rate incubation with SSCDO-5 strain was (22.13 ± 6.62)% while with FDd1 strain was (29.53 ± 5.51)%. The specificity of SSCDO-5 strain with D. officinale at seedling formation and development stage was not inherited or expressed in hybrid progenies, indicating that hybridization broke the symbiotic relationship of this specificity, which enabled hybrid progenies to establish new symbiotic relationship with different fungi. Our results do not support the hypothesis that the specificity of symbiotic fungi is an important limiting factor for the formation of hybrid progenies in Dendrobium. We speculate that the symbiotic relationship between Dendrobium plants and fungi during seedling differentiation and development is formed and established in the process of adapting to specific ecological environment.

Key words: symbiosis specificity, mycorrhizal fungi, Orchidaceae, Dendrobium, hybrid speciation, symbiotic seed germination

范紫腾, 毋钰灵, 王新菊, 李太强, 高江云. 共生真菌对兰科植物种间杂交后代种子萌发的效应. 植物生态学报, 2019, 43(4): 374-382. DOI: 10.17521/cjpe.2019.0048

FAN Zi-Teng, WU Yu-Ling, WANG Xin-Ju, LI Tai-Qiang, GAO Jiang-Yun. Effects of symbiotic fungi on seed germination of interspecific hybrid progenies in Orchidaceae. Chinese Journal of Plant Ecology, 2019, 43(4): 374-382. DOI: 10.17521/cjpe.2019.0048

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链接本文: https://www.plant-ecology.com/CN/10.17521/cjpe.2019.0048

https://www.plant-ecology.com/CN/Y2019/V43/I4/374

图/表 3

图1 三种石斛在不同处理、不同时期种子萌发及原球茎和幼苗形成情况。A, 铁皮石斛种子和SSCDO-5菌株共生培养30天时萌发的种子和形成的原球茎。B, 齿瓣石斛种子和FDd1菌株共生培养58天时形成的幼苗。C, 杂交石斛种子和FDd1菌株共生培养68天时的幼苗情况。D, 杂交石斛种子和SSCDO-5菌株共生培养68天时的幼苗情况。

Fig. 1 Seed germination, protocorm and seedling formation of three Dendrobium species under different treatments at different stages. A, Germinating seed and formed protocorm of D. officinale after 30 days incubation with SSCDO-5 strain. B, A seeding of D. devonianum after 58 days incubation with FDd1 strain. C, Seedings of hybrid after 68 days incubation with FDd1 strain. D, Seedings of hybrid after 68 days incubation with SSCDO-5 strain.

图2 三种石斛不同处理下种子萌发率(A、D、G)、原球茎形成率(B、E、H)和幼苗形成率(C、F、I)(平均值±标准误差)。柱子上方不同小写字母表示同一阶段不同处理之间差异显著(α = 0.05)。OMA, 不接菌的燕麦琼脂培养基作为营养缺乏对照处理; MS, 不接菌的MS培养基作为营养丰富对照处理; SSCDO-5, 燕麦培养基上接种SSCDO-5菌株处理; FDd1, 燕麦培养基上接种FDd1菌株处理菌的处理。

Fig. 2 Percentage of seed germination (A, D, G), protocorm (B, E, H) and seedling (C, F, I) formation of different treatments in three Dendrobium species (mean ± SE). Different lowercase letters above the bars represent significant differences between different treatments at the same stage (α = 0.05). OMA, oatmeal agar medium without fungal inoculation was used as nutrient-poor control treatment; MS, MS medium without fungal inoculation was used as nutrient-rich control treatment; SSCDO-5, treatment of fungal inoculation with SSCDO-5 strain on OMA medium; FDd1, treatment of fungal inoculation with FDd1 strain on OMA medium.

表1 不同处理三种石斛种子萌发率、原球茎形成率和幼苗形成率的多重比较(均值差±标准误差)

Table 1 Multiple comparisons on seed germination rate, protocorms formation rate and seedlings formation rate of different treatments for three Dendrobium species (mean ± SE)

多重比较 Multiple comparisons	铁皮石斛 D. officinale			齿瓣石斛 D. devonianum			杂交种 Hybrid
	种子萌发率 Seed germination rate	原球茎形成率 Protocorms formation rate	幼苗率 Seedlings formation rate	种子萌发率 Seed germination rate	原球茎形成率 Protocorms formation rate	幼苗率 Seedlings formation rate	种子萌发率 Seed germination rate	原球茎形成率 Protocorms formation rate	幼苗率 Seedlings formation rate
OMA-MS	-0.139 3 ± 0.058 2^*	0.000 0 ± 0.042 7	0.000 0 ± 0.053 4	-0.044 4 ± 0.071 1	-0.065 5 ± 0.063 9	-0.021 4 ± 0.051 6	-0.012 0 ± 0.058 1	-0.039 3 ± 0.053 0	-0.017 2 ± 0.064 4
OMA-SSCDO-5	-0.235 3 ± 0.057 7^***	-0.888 8 ± 0.042 3^***	-0.696 6 ± 0.052 9^***	0.312 1 ± 0.069 5^***	-0.354 8 ± 0.062 4^***	-0.096 8 ± 0.050 4	-0.036 9 ± 0.058 1	-0.704 0 ± 0.053 0^***	-0.221 3 ± 0.064 4^**
OMA-FDd1	-0.242 3 ± 0.058 2^***	-0.065 5 ± 0.042 7	0.065 5 ± 0.053 4	-0.094 8 ± 0.070 5	-0.651 7 ± 0.063 3^***	-0.436 8 ± 0.051 2^***	-0.070 1 ± 0.059 1	-0.800 4 ± 0.053 9^***	-0.295 3 ± 0.065 5^***
MS-SSCDO-5	-0.096 0 ± 0.058 2	-0.888 8 ± 0.042 7^***	-0.696 6 ± 0.053 4^***	0.356 5 ± 0.068 1^***	-0.289 4 ± 0.061 1^***	-0.075 3 ± 0.049 4	-0.024 9 ± 0.055 3	-0.664 8 ± 0.050 4^***	-0.204 0 ± 0.061 3^**
MS- FDd1	-0.102 9 ± 0.058 7	-0.006 6 ± 0.043 1	0.065 5 ± 0.053 8	-0.050 4 ± 0.069 2	-0.586 2 ± 0.062 1^***	-0.415 4 ± 0.050 2^***	-0.058 1 ± 0.056 3	-0.761 1 ± 0.0513 4^***	-0.278 0 ± 0.062 4^***
SSCDO-5- FDd1	-0.007 0 ± 0.058 2	0.823 3 ± 0.042 7^***	0.631 0 ± 0.053 4^***	-0.406 9 ± 0.067 5^***	-0.296 9 ± 0.060 6^***	-0.340 0 ± 0.049 0^***	-0.033 2 ± 0.056 3	-0.096 4 ± 0.051 3	-0.074 0 ± 0.062 4

表1 不同处理三种石斛种子萌发率、原球茎形成率和幼苗形成率的多重比较(均值差±标准误差)

Table 1 Multiple comparisons on seed germination rate, protocorms formation rate and seedlings formation rate of different treatments for three Dendrobium species (mean ± SE)

多重比较 Multiple comparisons	铁皮石斛 D. officinale			齿瓣石斛 D. devonianum			杂交种 Hybrid
	种子萌发率 Seed germination rate	原球茎形成率 Protocorms formation rate	幼苗率 Seedlings formation rate	种子萌发率 Seed germination rate	原球茎形成率 Protocorms formation rate	幼苗率 Seedlings formation rate	种子萌发率 Seed germination rate	原球茎形成率 Protocorms formation rate	幼苗率 Seedlings formation rate
OMA-MS	-0.139 3 ± 0.058 2^*	0.000 0 ± 0.042 7	0.000 0 ± 0.053 4	-0.044 4 ± 0.071 1	-0.065 5 ± 0.063 9	-0.021 4 ± 0.051 6	-0.012 0 ± 0.058 1	-0.039 3 ± 0.053 0	-0.017 2 ± 0.064 4
OMA-SSCDO-5	-0.235 3 ± 0.057 7^***	-0.888 8 ± 0.042 3^***	-0.696 6 ± 0.052 9^***	0.312 1 ± 0.069 5^***	-0.354 8 ± 0.062 4^***	-0.096 8 ± 0.050 4	-0.036 9 ± 0.058 1	-0.704 0 ± 0.053 0^***	-0.221 3 ± 0.064 4^**
OMA-FDd1	-0.242 3 ± 0.058 2^***	-0.065 5 ± 0.042 7	0.065 5 ± 0.053 4	-0.094 8 ± 0.070 5	-0.651 7 ± 0.063 3^***	-0.436 8 ± 0.051 2^***	-0.070 1 ± 0.059 1	-0.800 4 ± 0.053 9^***	-0.295 3 ± 0.065 5^***
MS-SSCDO-5	-0.096 0 ± 0.058 2	-0.888 8 ± 0.042 7^***	-0.696 6 ± 0.053 4^***	0.356 5 ± 0.068 1^***	-0.289 4 ± 0.061 1^***	-0.075 3 ± 0.049 4	-0.024 9 ± 0.055 3	-0.664 8 ± 0.050 4^***	-0.204 0 ± 0.061 3^**
MS- FDd1	-0.102 9 ± 0.058 7	-0.006 6 ± 0.043 1	0.065 5 ± 0.053 8	-0.050 4 ± 0.069 2	-0.586 2 ± 0.062 1^***	-0.415 4 ± 0.050 2^***	-0.058 1 ± 0.056 3	-0.761 1 ± 0.0513 4^***	-0.278 0 ± 0.062 4^***
SSCDO-5- FDd1	-0.007 0 ± 0.058 2	0.823 3 ± 0.042 7^***	0.631 0 ± 0.053 4^***	-0.406 9 ± 0.067 5^***	-0.296 9 ± 0.060 6^***	-0.340 0 ± 0.049 0^***	-0.033 2 ± 0.056 3	-0.096 4 ± 0.051 3	-0.074 0 ± 0.062 4

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