Structural development and physicochemical properties of starch in caryopsis of super rice with different types of panicle.

BACKGROUND: Starch is the main storage substance in rice caryopsis and its properties will determine the quality of rice. Super rice has been extensively studied due to its high-yield characteristics, but the knowledge of amyloplast development and starch quality in caryopsis of super rice especially with large panicle is limited. RESULTS: To address this, large panicle typed and normal panicle typed super rice cultivar Yongyou2640 (YY2640) and Nangeng9108 (NG9108) were investigated in this study. The development of amyloplast in YY2640 caryopsis was better than NG9108, showing faster degradation rate of pericarp amyloplast and better filling degree of endosperm amyloplast. Meanwhile, the starch granule of YY2640 presented as polyhedral shape with smooth surface and the granule size was slightly larger than NG9108. The starch of YY2640 exhibited the lower amylose content, ratio of amylose to amylopectin and the higher level of amylopectin short and long branch-chains compared with NG9108, but there was no significant difference in amylopectin branching degree between them. Two rice starches both showed the characteristics of A-type crystal, and the relative crystallinity and external ordered degree of YY2640 starch were higher than those of NG9108. Furthermore, YY2640 starch showed better pasting properties with lower pasting temperature, shorter pasting time, higher peak viscosity, trough viscosity, breakdown value and lower setback value because of lower apparent amylose content. CONCLUSIONS: Overall, the development and filling of amyloplast in YY2640 caryopsis were better than those of NG9108, thus leading to better starch quality of YY2640.

Transcriptome analysis of near-isogenic line provides novel insights into genes associated with panicle traits regulation in rice.

Panicle traits in rice impact yield and quality. The OsGRF4 gene encodes a growth-regulating factor controlling panicle traits, and was recently cloned. Gene expression profiling analysis can be used to study the molecular mechanisms underlying OsGRF4 regulation. Use of near-isogenic lines (NILs) reduces genetic background noise in omics studies. We compared transcriptome profiling of 7 cm long young panicles of NIL-Osgrf4 and NIL-OsGRF4 using RNAs sequence analyses. Eighty differentially expressed genes (DEGs) were identified. Our target gene OsGRF4 was up-regulated in NIL-OsGRF4 plants, which is consistent with a previous qPCR analysis. Hierarchical cluster analysis showed OsGRF4 is tightly clustered with the up-regulated DEG LOC_Os02g47320. Gene Ontology (GO) and KEGG analysis suggested that DEGs were primarily involved in somatic embryogenesis and chitinase activity. Two up-regulated DEGs, LOC_Os04g41680 and LOC_Os04g41620, were significantly enriched in the top 8 GO terms, and were over_represented in term of seed development, and may play key roles in grain shape regulation. The transcription factor Osmyb1 also exhibited differential expression between NILs, and may be is an important regulator of panicle traits. By searching reported functions of DEGs and by co-localization with previous identified quantitative trait loci (QTL), we determined that the pleiotropic gene OsGRF4 may also be involve in abiotic stress resistance. This study provides new candidates genes for further understanding the molecular mechanisms underlying rice panicle trait regulation.

Diversification of Bromelioideae (Bromeliaceae) in the Brazilian Atlantic rainforest: A case study in Aechmea subgenus Ortgiesia.

Aechmea subgenus Ortgiesia comprises ca. 20 species distributed in Brazil, Argentina, Paraguay, and Uruguay, with a center of diversity in the Brazilian Atlantic rainforest. We examined interspecific relationships of Ortgiesia based on Amplified Fragment Length Polymorphisms (AFLP). Ninety-six accessions belonging to 14 species of Ortgiesia were sampled, and genotyped with 11 AFLP primer combinations. The neighbor joining (NJ) tree depicted two main genetic groups within Aechmea subgenus Ortgiesia, and four subgroups. The NJ tree showed short internal branches, indicating an overall shallow genetic divergence among Ortgiesia species as expected for the recently radiated subfamily Bromelioideae. Our results suggest that hybridization and/or incomplete lineage sorting may have hampered the reconstruction of interspecific relationships in Aechmea subgenus Ortgiesia. The mapping of petal color (yellow, blue, pink, or white), inflorescence type (simple or compound), and inflorescence shape (ellipsoid, subcylindric, cylindric, or pyramidal) against the NJ tree indicated that these characters are of limited taxonomic use in Aechmea subgenus Ortgiesia due to homoplasy. An analysis of the current distribution of Ortgiesia identified the southern region of the Brazilian Atlantic rainforest, between latitudes of 26° and 27°S, as the center of diversity for the subgenus.

[Structure, ontogeny and vascularization of the flowers and inflorescences of Drimys granadensis (Winteraceae)]. / Estructura, ontogenia y vascularización de las flores e inflorescencias de Drimys granadensis (Winteraceae).

Structure, ontogeny and vascularization of the flowers and inflorescences of Drimys granadensis (Winteraceae). Drimys granadensis is a widespread species in montane forests of South and Central America. In this research, the structure, ontogeny, phyllotaxis and vascularization of the flowers and inflorescences of this species was studied in a population from the Eastern hills of Sabana de Bogota, Colombia. The methods used applied both optical microscopy, with astra blue-fuchsin staining, and scanning electron microscopy, using critical point dryed and gold-paladium metallized samples. Besides, results were compared with those of Drimys winteri, a widely studied species distributed in Chile and Argentina. Additionally, we studied the detail of the floral anatomy to determine the bracteal or calicine identity of the caliptra. I confirmed the proliferative status of the monothelic inflorescence, discarding alternative explanations of the terminal flower identity. I found that uniflorescences have an acropetal development until the terminal meristem becomes the terminal flower, then this flower develops rapidly resulting in a determined uniflorescence. I found pseudosyphonosthelic vascularization in peduncles and pedicels. Besides, I discovered some evidence in the vascular and anatomical structures, to consider the caliptra as the fusion product of various structures and therefore of calicine origin. The caliptra showed a whorled phyllotaxis, but the petals, stamens and carpels presented a spiral condition; phyllotaxis change was explained by the long time lapse between the initiation of the calyx and the corolla. I found great similarities among the inflorescences of D. granadensis and D. winteri; they were different in the proliferation start time, and in the frequent presence of nomophylls in D. granadensis, in contrast to the presence of reduced bracts and bracteoles in D. winteri inflorescences.

Estructura, ontogenia y vascularización de las flores e inflorescencias de Drimys granadensis (Winteraceae) / Structure, ontogeny and vascularization of the flowers and inflorescences of Drimys granadensis (Winteraceae)

Drimys granadensis is a widespread species in montane forests of South and Central America. In this research, the structure, ontogeny, phyllotaxis and vascularization of the flowers and inflorescences of this species was studied in a population from the Eastern hills of Sabana de Bogota, Colombia. The methods used applied both optical microscopy, with astra blue-fuchsin staining, and scanning electron microscopy, using critical point dryed and gold-paladium metallized samples. Besides, results were compared with those of Drimys winteri, a widely studied species distributed in Chile and Argentina. Additionally, we studied the detail of the floral anatomy to determine the bracteal or calicine identity of the caliptra. I confirmed the proliferative status of the monothelic inflorescence, discarding alternative explanations of the terminal flower identity. I found that uniflorescences have an acropetal development until the terminal meristem becomes the terminal flower, then this flower develops rapidly resulting in a determined uniflorescence. I found pseudosyphonosthelic vascularization in peduncles and pedicels. Besides, I discovered some evidence in the vascular and anatomical structures, to consider the caliptra as the fusion product of various structures and therefore of calicine origin. The caliptra showed a whorled phyllotaxis, but the petals, stamens and carpels presented a spiral condition; phyllotaxis change was explained by the long time lapse between the initiation of the calyx and the corolla. I found great similarities among the inflorescences of D. granadensis and D. winteri; they were different in the proliferation start time, and in the frequent presence of nomophylls in D. granadensis, in contrast to the presence of reduced bracts and bracteoles in D. winteri inflorescences.

Drimys granadensis es una especie de amplia distribución en los bosques montanos de Sur y Centro América. En esta investigación se estudiaron, mediante microscopía óptica y electrónica de barrido, la estructura, ontogenia, filotaxis y vascularización de sus flores e inflorescencias, y fueron comparadas con las de Drimys winteri, especie distribuida en Chile y Argentina. Adicionalmente, se buscó evidencia para determinar la identidad bracteal o calicina de la caliptra de sus flores. Se confirmó la condición monotélica proliferante de la inflorescencia, descartando explicaciones alternativas de identidad de la flor terminal. Las uniflorescencias presentan un desarrollo acrópeto, hasta que el meristemo terminal se transforma en flor terminal, entonces esta flor se desarrolla rápidamente dando lugar a una uniflorescencia determinada. La vascularización es pseudosifonostélica para pedúnculos y pedicelos. Se encontró evidencia en la vascularización y estructura anatómica para considerar la caliptra como el producto de fusión de varias estructuras y, por tanto, de origen calicino. La caliptra presentó una filotaxis verticilada, pero los pétalos, estambres y carpelos presentaron una filotaxis espiralada; el cambio se explicó por el tiempo prolongado entre la iniciación de cáliz y corola. Las inflorescencias de D. granadensis y D. winteri son muy similares; siendo diferente el tiempo de inicio de la proliferación y la frecuente presencia de nomófilos en las inflorescencias de D. granadensis, en contraste con la presencia de brácteas y bracteolas reducidas en D. winteri.

Inflorescences in Eriocaulaceae: taxonomic relevance and practical implications.

BACKGROUND AND AIMS: Inflorescences are thought to be of enormous taxonomic relevance; however, at the same time they are regarded as being notoriously difficult. This is partly due to the conflicting needs of floristics and evolutionary botany, but partly also due to the complicated and confusing terminology introduced by W. Troll and his school. METHODS: The branching patterns of representatives of the genera Eriocaulon, Syngonanthus and Paepalanthus have been studied in the field and from preserved material by scanning electron microscopy. Branching patterns and formation sequences have been analysed and documented in longitudinal schemes and diagrams. Repetitive units of different levels are detected and related to the body plans of other species of the family. KEY RESULTS: The repetition of very few different branching patterns on different levels of complexity may lead to highly complex inflorescences. However, terms are needed only for patterns; levels may be numbered consecutively. While complex inflorescences are often described as additions or aggregations of units, there is some evidence that complex inflorescences are often the result of fractionation of inflorescence meristems. CONCLUSIONS: Precise descriptions of inflorescences useful for diagnostics and phylogenetics can be much simpler than they often are today. If complex inflorescences are the result of meristem fractionation, intermediate morphotypes cannot be expected. On the other hand, such intermediate morphotypes should occur if a complex inflorescence is formed following an aggregation pathway. Unless the repetitive patterns shown here are not correlated to complementary gene activities the inflorescences are not fully understood.

Microsatellite markers for the endangered root holoparasite Dactylanthus taylorii (Balanophoraceae) from 454 pyrosequencing.

PREMISE OF THE STUDY: Microsatellite loci were isolated and developed as polymorphic markers for the New Zealand endemic root holoparasite Dactylanthus taylorii for use in population and conservation genetics studies. METHODS AND RESULTS: Shotgun 454 pyrosequencing was performed on genomic DNA pooled from three individuals of D. taylorii. From 61709 individual sequence reads, primers for 753 microsatellite loci were developed in silico and 72 of these were tested for consistent amplification and variability. Ten microsatellite loci were found to be polymorphic and consistently scorable when screened in 44 individuals from five geographically distant populations. The number of alleles per locus ranged from four to 16 with an average of 9.7, and average observed heterozygosity per locus was between 0.182 and 0.634. CONCLUSIONS: These polymorphic microsatellite markers establish an important resource for ongoing conservation initiatives and planned population genetic studies of D. taylorii.

Teosinte inflorescence phytolith assemblages mirror Zea taxonomy.

Molecular DNA analyses of the New World grass (Poaceae) genus Zea, comprising five species, has resolved taxonomic issues including the most likely teosinte progenitor (Zea mays ssp. parviglumis) of maize (Zea mays ssp. mays). However, archaeologically, little is known about the use of teosinte by humans both prior to and after the domestication of maize. One potential line of evidence to explore these relationships is opaline phytoliths produced in teosinte fruit cases. Here we use multidimensional scaling and multiple discriminant analyses to determine if rondel phytolith assemblages from teosinte fruitcases reflect teosinte taxonomy. Our results indicate that rondel phytolith assemblages from the various taxa, including subspecies, can be statistically discriminated. This indicates that it will be possible to investigate the archaeological histories of teosinte use pending the recovery of appropriate samples.

Morphological and qualitative characterisation of globe artichoke head from new seed-propagated cultivars.

BACKGROUND: Three new artichoke seed-propagated hybrids (Tempo, Opal and Madrigal) were compared with two standard cultivated varietal types [Catanese and Violet du Provence (VP)] in terms of head morphology, processing performance, nutritional or technological qualitative traits, in order to define their best use. RESULTS: Compared to the other genotypes, Opal and Madrigal had more rounded, heavier, larger heads, higher processing yield (>400 g of heart kg(-1) raw head) and lower total phenol (TP) content (2.4 g of gallic acid equivalents kg(-1) FW). VP gave a higher processing yield than Catanese and showed the highest TP content (6.5 g kg(-1) FW). Tempo hearts were more similar to those of VP in biometrical and chemical terms (P, Na, K, Ca); they had the highest dry matter content (163 g kg(-1) FW) and the waste left after peeling had the highest TP content. CONCLUSIONS: Hybrid artichokes, especially Opal and Madrigal, appear more suitable for the processing industry and also for fresh-cut production due to their highest processing yield and lowest total phenol content. Because of its high total phenol content, Tempo waste represents a possible source of natural antioxidant in the pharmaceutical field and in the food industry (as a food additive).

Preliminary survey of taxonomical problems, pharmacognostical characteristics, and chloroplast DNA polymorphisms of the folk medicinal herb Artemisia campestris from the Ryukyu Islands, Japan.

Artemisia campestris L. (Compositae) occurs naturally along the coastline of the Ryukyu Islands and has been traditionally used as a folk medicine for the treatment of liver and kidney disorders. The authors obtained specimens from the Ishigaki and Kume Islands of the Ryukyu Islands, Japan, and from the USA. A survey of the literature revealed that the Japanese name for A. campestris is Niitaka-yomogi or Riukiu-yomogi. Two distinct overall plant-form phenotypes were identified: an erect phenotype with long, upright, and straight main axis and assurgent branches; and a prostrate phenotype, having branches that are longer than the main axis and which grow along the ground. Except for the number of ray flowers, most of the flower head characters in the erect phenotypes were significantly larger than those in the prostrate phenotypes. In this experiment, the flower heads contained only small amounts of either capillarisin (<0.01-0.11 of the dry weight, % DW) and 6,7-dimethylesculetin (<0.01-0.30% DW), or none at all. DNA polymorphisms at two sites of the rpl16-rpl14 spacer region (nucleotide position 181-189 and 291-300 from the 5' end) revealed the existence of four different haplotypes. The number of adenines at nucleotide positions 291-300 appeared to be polymorphic within A. campestris from the Ryukyu Islands. Conversely, geographic differences between specimens from the Ryukyu Islands and USA manifested as a nine-base deletion at nucleotide positions 181-189. From a pharmacognostical context, the use of A. campestris flower heads as a substitute for Artemisiae capillaris Flos is not effective.