Production and cytological characterization of a synthetic amphiploid derived from a cross between Oryza sativa and Oryza punctata

Genome ◽  
2019 ◽  
Vol 62 (11) ◽  
pp. 705-714
Author(s):  
Kishor Kumar ◽  
Kumari Neelam ◽  
Gurpreet Singh ◽  
Jyotirmaya Mathan ◽  
Aashish Ranjan ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Interspecific Hybrid ◽  
Agronomic Traits ◽  
Flow Cytometric Analysis ◽  
Linkage Drag ◽  
Cultivated Rice ◽  
Substitution Lines ◽  
Oryza Punctata ◽  
Bundle Sheath Cells ◽  
Mother Cells

Oryza punctata Kotschy ex Steud. (BB, 2n = 24) is a wild species of rice that has many useful agronomic traits. An interspecific hybrid (AB, 2n = 24) was produced by crossing O. punctata and Oryza sativa variety Punjab Rice 122 (PR122, AA, 2n = 24) to broaden the narrow genetic base of cultivated rice. Cytological analysis of the pollen mother cells (PMCs) of the interspecific hybrids confirmed that they have 24 chromosomes. The F1 hybrids showed the presence of 19–20 univalents and 1–3 bivalents. The interspecific hybrid was treated with colchicine to produce a synthetic amphiploid (AABB, 2n = 48). Pollen fertility of the synthetic amphiploid was found to be greater than 50% and partial seed set was observed. Chromosome numbers in the PMCs of the synthetic amphiploid were 24II, showing normal pairing. Flow cytometric analysis also confirmed doubled genomic content in the synthetic amphiploid. Leaf morphological and anatomical studies of the synthetic amphiploid showed higher chlorophyll content and enlarged bundle sheath cells as compared with both of its parents. The synthetic amphiploid was backcrossed with PR122 to develop a series of addition and substitution lines for the transfer of useful genes from O. punctata with least linkage drag.

scholarly journals Segregation Distortion Observed in the Progeny of Crosses Between Oryza sativa and O. meridionalis Caused by Abortion During Seed Development

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 398
Author(s):  
Daiki Toyomoto ◽  
Masato Uemura ◽  
Satoru Taura ◽  
Tadashi Sato ◽  
Robert Henry ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Seed Development ◽  
Wild Rice ◽  
Lethal Gene ◽  
Chromosome 6 ◽  
Cultivated Rice ◽  
Substitution Lines ◽  
Putative Gene ◽  
Aa Genome ◽  
Recurrent Backcrossing

Wild rice relatives having the same AA genome as domesticated rice (Oryza sativa) comprise the primary gene pool for rice genetic improvement. Among them, O. meridionalis and O. rufipogon are found in the northern part of Australia. Three Australian wild rice strains, Jpn1 (O. rufipogon), Jpn2, and W1297 (O. meridionalis), and one cultivated rice cultivar Taichung 65 (T65) were used in this study. A recurrent backcrossing strategy was adopted to produce chromosomal segment substitution lines (CSSLs) carrying chromosomal segments from wild relatives and used for trait evaluation and genetic analysis. The segregation of the DNA marker RM136 locus on chromosome 6 was found to be highly distorted, and a recessive lethal gene causing abortion at the seed developmental stage was shown to be located between two DNA markers, KGC6_10.09 and KGC6_22.19 on chromosome 6 of W1297. We name this gene as SEED DEVELOPMENT 1 (gene symbol: SDV1). O. sativa is thought to share the functional dominant allele Sdv1-s (s for sativa), and O. meridionalis is thought to share the recessive abortive allele sdv1-m (m for meridionalis). Though carrying the sdv1-m allele, the O. meridionalis accessions can self-fertilize and bear seeds. We speculate that the SDV1 gene may have been duplicated before the divergence between O. meridionalis and the other AA genome Oryza species, and that O. meridionalis has lost the function of the SDV1 gene and has kept the function of another putative gene named SDV2.

RFLP analysis of the progeny from Oryza alta Swallen × Oryza sativa L.

Genome ◽  
1995 ◽  
Vol 38 (5) ◽  
pp. 913-918 ◽  
Author(s):  
Long Mao ◽  
Lihuang Zhu ◽  
Qin Zhou ◽  
Xianping Wang ◽  
Han Hu
Keyword(s):  
Oryza Sativa ◽  
Wild Rice ◽  
Oryza Sativa L ◽  
Rice Chromosome ◽  
Rflp Analysis ◽  
Wide Hybridization ◽  
Root Tip ◽  
Cultivated Rice ◽  
Mother Cells ◽  
Chromosome Segments

RFLP analyses were carried out in the progeny from a cross of two phylogenetically distant rice species, wild rice Oryza alta Swallen (CCDD, 2n = 48) and cultivated rice O. sativa L. (AA, 2n = 24). The sterile plants gave heterozygous RFLP patterns at most of the loci detected. They looked more like their wild rice parent, with 36 chromosomes in their root-tip cells and pollen mother cells. In two partially fertile plants, however, most of the markers that were used showed RFLP patterns similar to the cultivated parent, O. sativa. By cytological study, it was found that nearly one-third of the chromosomes had been eliminated in the partially fertile plants. Their seeds have short awns, which is a characteristic of their wild parent, O. alta. An introgression occurred in one of the partially fertile plants, which led to the discussion about a nonconventional mechanism in wide hybridization for transference of wild rice chromosome segments to cultivated rice chromosomes.Key words: RFLP, Oryza alta, rice, Oryza sativa, wide hybridization.

Full-length Transcriptome Reconstruction Reveals Genetic Differences in Hybrids of Oryza Sativa and Oryza Punctata With Different Ploidy and Genome Compositions

2021 ◽  
Author(s):  
Wenting He ◽  
Xianhua Zhang ◽  
Pincang Lv ◽  
Wei Wang ◽  
Jie Wang ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Single Molecule ◽  
Intron Retention ◽  
Alternative Polyadenylation ◽  
Genetic Differences ◽  
Nucleic Acid Binding ◽  
Cultivated Rice ◽  
Seeding Rate ◽  
New Genes ◽  
Oryza Punctata

Abstract Background: Allopolyploid breeding is an efficient technique for improving the low seeding rate of autotetraploids in plant breeding and one of the most promising breeding methods. However, there have been few comprehensive studies of the posttranscriptional mechanism in allopolyploids.Results: By crossing cultivated rice (Oryza sativa, genome AA) with wild rice (Oryza punctata, genome BB), we created hybrid rice lines with different ploidy and genome compositions [diploid F01 (AB), allotetraploid F02 (AABB) and F03 (AAAB)]. The genetic differences of the hybrids and the mechanism of allopolyploid breeding dominance were revealed through morphological and cytological observations and single molecule real-time sequencing techniques. The tissues and organs of allotetraploid rice F02 exhibited "gigantism" and the highest levels of fertility. The numbers of non-redundant transcripts, gene loci and new isoforms in the polyploid rice lines were higher and the isoform lengths greater than those of the diploid line. Moreover, alternative splicing (AS) events occurred twice as often in the polyploid rice lines than the diploid line. During these events, intron retention dominated. Furthermore, a large number of new genes and isoforms specific to the lines of different ploidy were discovered. Conclusions: The results indicated that alternative polyadenylation (APA) and AS events contributed to the complexity and superiority of polyploids in the activity of translation regulators, nucleic acid binding transcription factor activities and the regulation of molecular function. Therefore, these APA and AS events in allopolyploid rice were found to play a role in regulation. Our study provides new germplasm for polyploid rice breeding and reveals complex regulatory mechanisms that may be related to heterosis and fertility.

scholarly journals High-Quality Genomes and High-Density Genetic Map Facilitate the Identification of Genes From a Weedy Rice

2021 ◽  
Vol 12 ◽  
Author(s):  
Fei Li ◽  
Zhenyun Han ◽  
Weihua Qiao ◽  
Junrui Wang ◽  
Yue Song ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Genetic Map ◽  
Agronomic Traits ◽  
Rice Variety ◽  
Heading Date ◽  
High Density ◽  
Weedy Rice ◽  
Rice Breeding ◽  
Cultivated Rice ◽  
High Quality

Genes have been lost or weakened from cultivated rice during rice domestication and breeding. Weedy rice (Oryza sativa f. spontanea) is usually recognized as the progeny between cultivated rice and wild rice and is also known to harbor an gene pool for rice breeding. Therefore, identifying genes from weedy rice germplasms is an important way to break the bottleneck of rice breeding. To discover genes from weedy rice germplasms, we constructed a genetic map based on w-hole-genome sequencing of a F2 population derived from the cross between LM8 and a cultivated rice variety. We further identified 31 QTLs associated with 12 important agronomic traits and revealed that ORUFILM03g000095 gene may play an important role in grain length regulation and participate in grain formation. To clarify the genomic characteristics from weedy rice germplasms of LM8, we generated a high-quality genome assembly using single-molecule sequencing, Bionano optical mapping, and Hi-C technologies. The genome harbored a total size of 375.8 Mb, a scaffold N50 of 24.1 Mb, and originated approximately 0.32 million years ago (Mya) and was more closely related to Oryza sativa ssp. japonica. and contained 672 unique genes. It is related to the formation of grain shape, heading date and tillering. This study generated a high-quality reference genome of weedy rice and high-density genetic map that would benefit the analysis of genome evolution for related species and suggested an effective way to identify genes related to important agronomic traits for further rice breeding.

scholarly journals Performance of the agronomic traits of six advanced promising lines of red rice (oryza sativa l.) grown on the paddy field

2021 ◽  
Vol 681 (1) ◽  
pp. 012033
Author(s):  
G R Sadimantara ◽  
E Febrianti ◽  
LO Afa ◽  
S Leomo ◽  
Muhidin ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Paddy Field ◽  
Agronomic Traits ◽  
Oryza Sativa L ◽  
Red Rice

Weedy Rice Diversity in Southern Brazil

Weed Science ◽  
2021 ◽  
pp. 1-37
Author(s):  
Leonard Bonilla Piveta ◽  
José Alberto Noldin ◽  
Nilda Roma-Burgos ◽  
Vívian Ebeling Viana ◽  
Lariza Benedetti ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Flowering Time ◽  
Weed Management ◽  
Phenotypic Diversity ◽  
Weedy Rice ◽  
Phenotypic Traits ◽  
Southern Brazil ◽  
Variable Response ◽  
Cultivated Rice ◽  
Flowering Synchrony

Abstract Weedy rice (Oryza sativa L.) is one of the most troublesome weeds affecting rice (Oryza sativa L.) production in many countries. Weedy rice control is difficult in rice fields because the weed and crop are phenotypically and morphologically similar. Weedy rice can be a source of genetic diversity to cultivated rice. Thus, this study aimed to characterize the morphological diversity of weedy rice in Southern Brazil. Qualitative and quantitative traits of 249 accessions from eight rice growing mesoregions in Rio Grande do Sul (RS) and Santa Catarina (SC) states were analyzed. For each accession, 24 morphological descriptors (14 qualitative and 10 quantitative) were evaluated. All the 249 accessions from RS and SC are of indica lineage. Considering all the phenotypic traits evaluated, the accessions separated into 14 distinct groups. One of the largest groups consisted of plants that were predominantly tall and with green leaves, intermediate shattering, and variable in flowering time. Distinct subgroups exist within larger clusters, showing discernable phenotypic diversity within the main clusters. The variability in flowering time was high (77 to 110 d after emergence), indicating high potential for flowering synchrony with rice cultivars and, consequently, gene flow. This indicates the need to remove escapes when planting herbicide-resistant rice. Thus, weedy rice populations in Southern Brazil are highly diverse and this diversity could result in variable response to weed management.

scholarly journals Bacterial Flora of Endophytes in the Maturing Seed of Cultivated Rice (Oryza sativa)

2005 ◽  
Vol 20 (3) ◽  
pp. 168-177 ◽  
Author(s):  
Suguru Okunishi ◽  
Kentaro Sako ◽  
Hironobu Mano ◽  
Ayumi Imamura ◽  
Hisao Morisaki
Keyword(s):  
Oryza Sativa ◽  
Bacterial Flora ◽  
Cultivated Rice
Sign in / Sign up

Export Citation Format

Share Document