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为了解不同抚育采伐方式对倒木分布格局的影响,采用点格局分析法分析不同抚育采伐方式下兴安落叶松原始林、渐伐林和皆伐林内主要树种及不同径级倒木分布格局。结果表明:(1)兴安落叶松原始林、渐伐林、皆伐林中倒木分布格局显著差异,其中原始林随研究尺度增大既有聚集分布也有随机分布,渐伐林均呈显著聚集分布,皆伐林在1~14 m尺度上呈显著聚集分布,其余尺度为随机分布。(2)同原始林相比,渐伐林和皆伐林内兴安落叶松树种倒木均在小尺度呈显著聚集分布,大尺度呈随机分布,而白桦树种倒木均以随机分布为主,只伴有小范围聚集分布。(3)不同抚育采伐方式对小径级倒木分布格局影响显著,对中径级和大径级倒木影响较少。 相似文献
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红麻细胞质雄性不育系小孢子败育的细胞学观察 总被引:6,自引:0,他引:6
对同质异核的红麻细胞质雄性不育系L23A和K03A的小孢子发生和败育过程进行了细胞学比较观察。结果发现,2个不育系的败育过程有一定的相似性,败育都发生在四分体及单核小孢子时期;单核小孢子外壁发育都出现异常,小孢子原生质收缩变形或解体;花药壁的中层延迟解体,绒毡层出现细胞融合、液泡化、提前脱离药壁进入药室和过早解体等异常行为。但两者败育的过程又有一定差异,单核早中期,L23A的小孢子发育基本正常,而K03A的小孢子外壁发育不良,壁薄且质脆、易破损,刺稀少细小;L23A的小孢子外壁在单核后期解体成为念珠状,而K03A的小孢子外壁在发育过程中破损、逐渐溶解;小孢子外壁解体过程中,L23A的小孢子原生质收缩为核质不分的一团,而K03A的小孢子原生质逐渐解体。 相似文献
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哈克尼西棉细胞质雄性不育系小孢子发生的超微结构观察 总被引:6,自引:3,他引:3
哈克尼西棉细胞质雄性不育(CMS)研究始于美国,因其具有不育性稳定、完全和保持系广泛等优点,受到棉花育种者的广泛重视,但其不育机理还不清楚。不同发育时期花药的细胞形态学观察,有助于了解CMS系雄性不育机理。光学显微镜下观察发现,不育系“DES-HAMS277”小孢子败育主要发生在造孢细胞增殖和小孢子母细胞形成期,且在减数分裂期彻底败育,不能形成四分体。但由于光学显微镜的局限性,对败育过程中小孢子和绒毡层在细微结构方面发生什么变化不清楚。不育系“DES-HAMS277”小孢子败育的超微结构未见报道。因此,本文以保持系花药为对照,… 相似文献
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小麦D型细胞质雄性不育系和保持系小孢子发育的超微结构观察 总被引:2,自引:0,他引:2
对小麦D型细胞质雄性不育系和保持系小孢子发育的超微结构观察发现,D型不育系小孢子在“小液泡期”即表现出败育迹象。花粉败育过程中,小孢子液泡膜和细胞质膜断裂破碎,细胞质解体,线粒体、质体、内质网等细胞器解体或退化,绒毡层持续不解体,并缺少乌氏体的分泌。小孢子细胞解体顺序为:细胞膜首先断裂,细胞质分解变稀薄,然后是核膜断裂,细胞核降解,细胞质及细胞核降解物质充满整个药室,最后核仁解体。 相似文献
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高粱A2型细胞质雄性不育系小孢子发生的细胞学观察和减数分裂染色体行为分析 总被引:1,自引:0,他引:1
高粱A2型细胞质雄性不育性(CMS)的细胞质来源于IS12662C, A2细胞质杂交种目前已用于生产。本文以A2/B2V4为材料,对A2 CMS小孢子败育过程作了细胞学观察,并对小孢子败育过程中减数分裂的染色体行为作了分析。研究发现,在A2雄性不育系A2V4的花药发育过程中,绒毡层细胞不形成或提前解体;绒毡层细胞畸形化;绒毡层细胞虽发育正常,但小孢子母细胞减数分裂行为异常;这些都导致小孢子退化。A2细胞质雄性不育花粉母细胞减数分裂行为从后期Ⅰ开始出现异常,同源或姊妹染色体向两极分离时滞后或不分裂;染色体多倍化;一个细胞内出现多核和多核仁现象,最终导致小孢子败育。 相似文献
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高粱A2型细胞质雄性不育系小孢子发生的细胞学观察和减数分裂染色体行为分析 总被引:4,自引:0,他引:4
高粱凡型细胞质雄性不育性(CMS)的细胞质来源于IS12662C,A2细胞质杂交种目前已用于生产。本文以A2/B2 V4为材料,对A2CMS小孢子败育过程作了细胞学观察,并对小孢子败育过程中减数分裂的染色体行为作了分析。研究发现,在A2雄性不育系A2V4的花药发育过程中,绒毡层细胞不形成或提前解体;绒毡层细胞畸形化;绒毡层细胞虽发育正常,但小孢子母细胞减数分裂行为异常;这些都导致小孢子退化。A2细胞质雄性不育花粉母细胞减数分裂行为从后期Ⅰ开始出现异常,同源或姊妹染色体向两极分离时滞后或不分裂;染色体多倍化;一个细胞内出现多核和多核仁现象,最终导致小孢子败育。 相似文献
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为了揭示洋葱雄性不育小孢子败育的时期和方式,试验利用石蜡切片技术,在光学显微镜下观察了洋葱雄性不育材料0127A及可育材料0127B的小孢子发育过程和各时期的形态特征.结果发现,雄性不育材料0127A的小孢子败育发生在单胞花粉粒时期,小孢子的细胞质被降解成空壳,染色浅,缺乏营养物质而败育. 相似文献
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棉花晋A细胞质雄性不育系小孢子发生的显微和超微结构观察 总被引:12,自引:4,他引:12
研究了棉花晋 A细胞质雄性不育系的细胞学特征。结果表明 ,1晋 A不育系雄性败育的主要时期是在造孢细胞增殖——小孢子母细胞形成时期。大部分小孢子母细胞在形成过程中退化解体 ;少数小孢子母细胞能进一步发育并开始减数分裂 ,但都仅停留在减数分裂前期 ,该不育系绒毡层提早解体与小孢子母细胞解体有关。 2小孢子母细胞和绒毡层细胞中的线粒体异常 ,对晋 A不育系小孢子败育有直接的影响。线粒体异常表现的特征为 :线粒体肿胀破裂 ,内嵴溶解、消失 相似文献
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Rafiq Ahmad Mahmood-ul- Hassan Ghanan B. Akhtar Sadia Saeed Sabaz A. Khan Muhammad Kausar Nawaz Shah Nadeem Khan 《Plant Breeding》2020,139(5):988-995
Onion is one of the major vegetable crops in terms of production as well as consumption. In the current research, available onion genetic stock was evaluated to identify male-sterile lines and produce high-yielding F1 hybrids for future breeding programmes. A mitochondrial DNA-based marker was mapped and correlated with phenotypic traits to isolate male-sterile plants. Based on the floral and pollen structure, nine putative male-sterile lines were identified. On the other hand, for nuclear marker identification at Ms locus, two sets of primers were used, one for Ms dominant allele and another for sterile and maintainer plants. Results revealed that 70% of open pollinated varieties (OPVs) possess plants with sterile cytoplasm coupled with genetic sterility at Ms locus, called sterile “A” line. Approximately 20% of plants in some genotypes were identified with normal (N) cytoplasm having recessive fertility gene at Ms locus, called maintainer “B” line. Based on the present findings, “A”, “B” and “R” (restorer line), future F1 hybrid seed production systems in onion is discussed. 相似文献
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本研究旨在开发稳定可靠的洋葱育性位点分子标记,并将其应用于育种实践,筛选育种系,从而缩短育种周期,节省育种成本,加速洋葱杂交种的培育进程。以洋葱育性恢复Ms座位的AFLP序列为基础,采用序列比对分析、PCR检测和表型分析等方法,开发、鉴定、应用了WH-SSR-1分子标记。结果表明:WH-SSR-1标记与Ms位点紧密连锁,Ms位点基因型为纯合显性MsMs时,有1条102 bp的扩增带;纯合隐性msms时,有1条99 bp的扩增带;杂合Msms时,有102 bp和99 bp两条扩增带。32份洋葱材料的验证结果证实了Ms座位的标记类型与基因型完全相符。随后从4个OP群体中直接获得了2个配套的不育系与保持系,‘吊玉’和‘天正红玉’因未检测到保持株或不育株,无法简单实现配套。WH-SSR-1标记与Ms位点紧密连锁,能够将其用于育种系筛选的育种实践,从OP群体中直接选择保持株和不育株,同时实现两系配套。 相似文献
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PEI Wen-Feng WU Jian-Yong XING Chao-Zhu GUO Li-Ping QI Ting-Xiang WANG Hai-Lin 《棉花学报》2013,25(6):478-485
This study aimed to analyze the expression level and relationship between miR156 and its target gene TBCC (Tubulin binding Cofactor C) in buds of Gossypium at different developmental stage in a cytoplasmic male sterile(CMS) line and its maintainer line, to clone the full-length cDNA of the TBCC gene, and to determine the possible role of the TBCC gene in pollen development. Real-time RT-PCR showed that the expression levels of miR156 gradually increased with the development of pollen between the CMS line and the maintainer line. The expression of GhTBCC was strikingly complementary with the expression of miR156 in the maintainer line, but showed very low expression levels in the CMS line, which demonstrated that TBCC is related to male sterility. The full-length cDNA sequence of TBCC was cloned from the buds of the maintainer line, and the gene was named as GhTBCC. The CDS of GhTBCC is 1713 bp and encodes a predicted protein of 570 amino acids with a predicted molecular weight of 62.79 kDa. Conserved TBCC and CARP domains were observed in the predicted protein sequence. GhTBCC showed 81 %, 80 %, and 77 % sequence similarity to the TBCC protein sequences of Populous trichocarpa, Ricinus communis, and Arabidopsis thaliana, respectively. 相似文献
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Segregation studies following the transfer of the gene wi to different cytoplasm types, which have been distinguished by means of restriction fragment length polymorphism analyses using mitochondrial gene probes, revealed the formation of the wi‐sterility in each of the four cytoplasms examined. The male sterility is therefore only caused by the nuclear wi gene, i.e. an additional factor of a specific cytoplasm can be excluded. Hence, the wi‐sterility proved to be a genic male sterility (GMS) and not a cytoplasmic male sterility (CMS). The expression of the wi‐sterility appears to be stable, since it is not affected by high temperatures or tetracycline. Accordingly, a temporary pollen production, which would allow self‐fertilization for the maintenance of sterile lines, cannot be induced by controlling these environmental factors. In terms of hybrid breeding, this GMS therefore has no advantage over the previously described CMS system. 相似文献
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玉米基因雄性不育双杂合保持系的选育研究 总被引:5,自引:2,他引:5
本研究从1982年开始,选用玉米ms1、ms2和ms10三个雄性核不育基因以及易位断点与相应ms基因紧密连锁的T4-6b、T9-10a、T4-10f和T6-10(5519)四个易位系作为基础材料,采用细胞遗传技术育成若干个骨干自交系的基因雄性不育双杂合保持系。至今,已选育出黄早四和Mo17背景的ms2基因杂合保持系。保持系与ms2基因不育系杂交,子代 相似文献
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