Sexual reproduction is the default mode in apomictic Hieracium subgenus Pilosella, in which two dominant loci function to enable apomixis
نویسندگان
چکیده
منابع مشابه
Sexual and apomictic reproduction in Hieracium subgenus pilosella are closely interrelated developmental pathways.
Seed formation in flowering plants requires meiosis of the megaspore mother cell (MMC) inside the ovule, selection of a megaspore that undergoes mitosis to form an embryo sac, and double fertilization to initiate embryo and endosperm formation. During apomixis, or asexual seed formation, in Hieracium ovules, a somatic aposporous initial (AI) cell divides to form a structurally variable aposporo...
متن کاملChromosomes carrying meiotic avoidance loci in three apomictic eudicot Hieracium subgenus Pilosella species share structural features with two monocot apomicts.
The LOSS OF APOMEIOSIS (LOA) locus is one of two dominant loci known to control apomixis in the eudicot Hieracium praealtum. LOA stimulates the differentiation of somatic aposporous initial cells after the initiation of meiosis in ovules. Aposporous initial cells undergo nuclear proliferation close to sexual megaspores, forming unreduced aposporous embryo sacs, and the sexual program ceases. LO...
متن کاملSporophytic ovule tissues modulate the initiation and progression of apomixis in Hieracium
Apomixis in Hieracium subgenus Pilosella initiates in ovules when sporophytic cells termed aposporous initial (AI) cells enlarge near sexual cells undergoing meiosis. AI cells displace the sexual structures and divide by mitosis to form unreduced embryo sac(s) without meiosis (apomeiosis) that initiate fertilization-independent embryo and endosperm development. In some Hieracium subgenus Pilose...
متن کاملpilosella plants are better inter - specific , while apomictic plants are better intra - specific competitors
Apomixis, asexual reproduction through seeds, occurs in over 40 plant families. This widespread phenomenon can lead to the fixation of successful genotypes, resulting in a fitness advantage. On the other hand, apomicts are expected to lose their fitness advantage if the environment changes because of their limited evolutionary potential, which is due to low genetic variability and the potential...
متن کاملGenetic analyses of the inheritance and expressivity of autonomous endosperm formation in Hieracium with different modes of embryo sac and seed formation
Background and Aims Apomixis, or asexual seed formation, in polyploid Hieracium subgenus Pilosella species results in clonal progeny with a maternal genotype. An aposporous embryo sac forms mitotically from a somatic cell, without prior meiosis, while embryo and endosperm formation is fertilization independent (autonomous). The latter two developmental components are tightly linked in Hieracium...
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ژورنال
عنوان ژورنال: The Plant Journal
سال: 2011
ISSN: 0960-7412
DOI: 10.1111/j.1365-313x.2011.04556.x