Length Of Caryopsis Research Articles

Inter-relações genéticas de causa e efeito para atributos de qualidade de grãos de arroz irrigado

Abstract The objective of this work was to determine the genetic correlations and the direct and indirect associations of agronomic traits and grain quality attributes with the percentage of whole grains in flood irrigated rice. The experiment was carried out in two environments, in a randomized complete block design with three replicates, using 23 irrigated rice genotypes. The evaluated traits were: percentage of whole grains, caryopsis length, caryopsis width, panicle length, panicle weight, 1,000 grain weight, days to flowering, percentage of chalky grains with white belly, total chalky area, total whiteness, vitreous whiteness, and defects in coloring. The percentage of grains with white belly and total chalky area were positively correlated, whereas the percentage of grains with white belly and vitreous whiteness were negatively correlated. The traits caryopsis width, percentage of chalky grains with white belly, panicle weight, and 1,000 grain weight showed indirect effects on whole-grain yield response according to total chalky area and total whiteness. Total chalky area and total whiteness are the factors that most negatively influence the percentage of whole grains according to the genotypic correlations and direct effects.

Gene action and genetic parameters of characters related to rice grain quality

AbstractInformation about gene action, heritability, heredity, and potential gain estimated by selecting these characters is scarce. This study aims to estimate genetic parameters related to physical attributes of rice (Oryza sativa L.) grain quality. The crosses “BR/IRGA 409″ × “BRS Bojuru” and their reciprocal were performed, obtaining F1 and F2 generations and backcrosses (BC1 and BC2). After obtaining seeds, the experiment was conducted following a completely randomized design with replications determined by the total number of plants of each generation. Total chalky area (CA), white core (WC), vitreous whiteness (VW), caryopsis length (CL), caryopsis width (CW), caryopsis length × width (CL/CW), percentage of whole grains (WHO), and broken grains (BG) were evaluated. The experiment analyzed means and variances and genetic parameters of generations based on a complete model and additive‐dominant model. The physical attributes are inherited quantitatively, and the main genetic effect is the additive. However, there is a great environmental influence on the characters studied. The BR/IRGA 409 × BRS Bojuru cross makes it possible to obtain a greater genetic gain in the selection of chalky grain characters (CA, WC, and VW) as they express a narrower heritability, whereas BRS Bojuru × BR/IRGA 409 makes it possible to obtain a greater genetic gain in the selection of CL, CW, CL/CW, WHO, and BG. Parent plants affect the type of gene action. A gene action of partial dominance, overdominance, and complete dominance occurred among the physical attributes of grain quality.

Creating Tetraploid Lines of Sweet Corn (Zea Mays Saccharata) and Studying Biochemical Content of Their Grain

A collection of tetraploid sweet corn has been created on the basis of Baksanskaya Sugary var. (VIR catalog no. k-23426) obtained from dent corn tetraploid population MRPP-20 characterized with high grain yield of its ear. The variety has been created by inbreeding separate caryopses homozigotic for su1 and su2 genes (sugary endosperm); the caryopses were selected from MRPP-20 population with subsequent selection work for valuable traits during a number of generations. The collection includes over 300 specimens, among them there are genotypes promising for selection of foodcrop sweet corn. The research was conducted into principal phenotypic traits of the plant and chemical components of its caryopsis (protein, starch, oil). Analysis has shown that the chemical composition of grain varies widely. Structural phenotypic traits of vegetative organs differ mainly in the number of ears per plant, ear size, number of seeds per ear and the number of seed rows, caryopsis length, color of corncob and the caryopsis itself. Specimens with high (17.0–18.0 %) and low (11.0–12.0 %) protein content, high (9.0–10.0 %) and low (5.0–6.0 %) oil content, high (66.0–67.0 %) and low (60.0–61.0 %) starch content in caryopses were produced. Specimens have been obtained that combine high starch content with low oil content (C-1042) and vice versa (C-1114, C-1116), with low protein and oil content in a combination with high starch content (C-1180, C-1370). The research results allowed choosing starting material for selection work with hybrids of sweet corn to get predefined flavor properties.

Iron biofortification in rice: in search of morphological traits for indirect selection in breeding programs

Iron (Fe) deficiency is an important cause of health concern in developing countries, demanding mitigation strate­gies to fight this disorder. The biofortification of staple foods, such as rice ( Oryza sativa L.), could be achieved via the development of improved cultivars. Iron quantification is relatively costly and time-consuming, making its rou­tine use impracticable in breeding programs. Therefore, the identification of traits to be used in indirect selection strategies would be of high interest. This study aimed to find promising traits for use in indirect selection programs aiming Fe biofortification in rice grains. A diverse set of 95 rice genotypes, mostly Brazilian, was grown at South­ern Brazil, in 2016/2017, and Fe content in brown and polished grains, as well as other 12 morphological traits, were assayed. Analysis of variance, linear correlation, and path analysis were carried out. Different levels of asso­ciation between traits were found, being panicles per plant and caryopsis width the most promising for use in indi­rect selection aiming increased Fe content in both brown and polished rice. However, secondary traits, such as caryopsis length, have also to be considered when performing selection aiming Fe biofortification in the cereal.

Morpho-phenology and chromosome number of Iranian Bromus danthoniae Trin. genotypes

ABSTRACT- Bromus danthoniae Trin. is an annual grass species which grows mainly on dry grassy rocky mountain slopes and grassy steppe, and is grazed by many herbivores and recognized as a useful pasture plant. The chromosome number, morphological and anatomical traits of 82 genotypes of B. danthoniae belonging to three sub-taxa were investigated. Twenty-seven quantitative and 20 qualitative morphological traits were evaluated. The results of analysis of variance showed that B. danthoniae genotypes varied significantly for all quantitatively tested traits. Based on cluster analysis, the genotypes were divided into four groups which mostly corresponded to their subspecies identities. According to correlation analysis, lemma length had strong positive correlations with other traits such as awn length (r=0.55**), lemma width (r=0.72**) and caryopsis length (r=0.84**). In addition, lemma width was significantly correlated with the traits like floret number per spikelet (r=0.47**) and caryopsis length (r=0.58**). Based on factor analysis, the first three factors encompass about 51% of total variation. Overall, lemma length and lemma width were the two reliable traits for morphological investigations in this species. The results of chromosome counting showed that B. danthoniae subsp. danthoniae and B. danthoniae var.lanuginusos Roshev. were diploid (2n=2x=14) whereas B. danthoniae subsp. pseudodanthoniae (Drobov) H. Scholz was tetraploid (2n=4x=28). The results of leaf surface anatomy showed that tetraploid genotypes had larger stomata but lower stomatal density than the diploid ones, thus a comprehensive relationship between genome size and guard cell size cannot be ruled out as a plausible explanation for differentiating the ploidy levels. The high morphological variations among the B. danthoniae genotypes explain the habitat distribution of this species and enable us to incorporate this knowledge into practice by exploiting the variation for improvement of pasture production.

The adaptive value of grass traits in response to grazing

Grazing is associated with several plant traits that may confer resistance to herbivores. However, cross-species analyses do not allow for the differentiation between adaptive evolution and common ancestry. In this study, we evaluated the effect of grazing on 5 morphological traits in 41 native grasses growing in natural grasslands of Uruguay and investigated whether such effects are independent of phylogeny. We used data of grass species from 17 paired, grazed and ungrazed plots located in different regions of natural grasslands of Uruguay. For each species, we calculated the Grazing Response Index (GRI) and estimated the culm length, blade length, blade width, blade length/width ratio and caryopsis length. Trait values were calculated as the mean of the maximum and minimum values reported in a public database. We assessed the relationship between the GRI and the morphological traits using cross-species correlations, and we re-examined the correlations using phylogenetically controlled comparative analysis. Culm length and blade length were significantly correlated with the GRI. Species with higher culms and longer blades diminished their cover under grazing. This association remained significant after statistical control of phylogenetic relatedness among species. By contrast, blade width, blade length/width ratio and caryopsis length did not show any significant relationship with the GRI. Many studies in temperate grasslands recognized that several plant traits respond to grazing but were rarely evaluated in a phylogenetic context. Our results are consistent with the idea that grazing is a selective force with a clear effect on the evolution of grass stature, selecting smaller plants with shorter blades.

Caryopsis micromorphological survey of Sorghum (Poaceae)—Taxonomic implications

Caryopsis micromorphological characters of 25 Sorghum species were studied using stereoscopic microscopy and scanning electron microscopy. There are three caryopsis shapes, including obovate-elliptic, ovate-elliptic and subulate; two patterns of stylopodia, including with or without an apical tuft of unicellular microhairs; and five spermoderm sculpture patterns, that is, reticulate with wavy cell walls, reticulate with straight cell walls, substriate, undulating and rugose in Sorghum. Caryopsis size and stylopodium persistence pattern have limited taxonomic application at the infrageneric level, while the caryopsis shapes show a certain taxonomic significance at the infrageneric level and spermoderm sculpture patterns are important diagnostic characters at the interspecific level in Sorghum. The separation of Sorghum sudanense from S. × drummondii is supported by our result of caryopsis size and spermoderm sculpture patterns. Consistent micromorphological characters of stylopodium persistence, dorsoventral compression, embryo proportion (the ratio of embryo to caryopsis length) and hilum proportion (the ratio of hilum to caryopsis length) are firstly found in Sorghum. Caryopsis micromorphological characters provide evidence that Sorghum is a highly heterogeneous genus at the micromorphological level.

Seed Diversity and Utilization of the Upland Rice Landraces and Traditional Varieties from Selected Areas in Bukidnon, Philippines

Enhancing upland rice production is one solution to achieve rice sufficiency in the country. Improved genotypes contribute to this goal at a relatively low cost to farmers, but available resources need to be assessed first. This study determined the availability of upland rice landraces and traditional varieties (URLTVs) in selected areas of Bukidnon, estimated the seed diversity of available genotypes, and documented their use. Twenty-four Barangays from 10 municipalities and 2 cities were surveyed from November 2010 to May 2011. Interviews (n=45), seed sourcing, and evaluation of 13 seed traits were done. One hundred forty URLTVs were collected, of which 82 (59%) were from San Fernando, Bukidnon whose peoples were mostly of the Matigsalug tribe. Shannon-Weaver Diversity estimates for 100 seed weight, grain length and width, grain thickness, caryopsis length and width, and lemma: apiculus color showed high diversity (H’=0.76 to 0.88). URLTVs were grown for household consumption, church offering and for special occasions, and to reduce chemical inputs. For the Matigsalugs, their URLTVS serve to strengthen their cultural beliefs and are trademarks for their tribal group. Collection from other areas of Bukidnon needs to be done to ascertain other available germplasm and possible threats to these plant genetic resources. Keywords - plant genetics, Oryza sativa, agro-ecosystem diversity, rice production, upland rice, Bukidnon, Philippines

Functional traits of grasses growing in open and shaded habitats

The amount of light available for photosynthesis is a key environmental factor that shapes the form and function of plants. Several plant traits affect the manner in which different species fix carbon during vegetative growth. Under the hypothesis that grasses respond to environmental selective pressures, we analyzed the differences in certain leaf, culm, and regenerative traits of 283 native Uruguayan grasses growing in open (grassland) and shaded (forest) habitats. In order to differentiate the phylogenetic effects from the adaptive changes to current local conditions, we used phylogenetically controlled comparative analysis. We found that the divergence of grass species between grasslands and forests was accompanied by changes in leaf traits. Narrow and filiform blades (higher length/width ratio) were favored in species growing in grasslands, while wider and oval blades were favored in species growing in forests. The response of the leaf blades in forests was probably directed towards maximizing light interception, while in grasslands could be linked to the loss of water and heat. In contrast, we found that neither the culm nor the caryopsis length exhibited significant evolutionary changes associated with open or shaded habitats. Our results highlight the functional significance and adaptive value of the width and shape of the grass blades to the current environment.

Systematic Study of Bromus danthoniae (Poaceae) Native to Iran

In this study different varieties of Bromus danthoniae in Iran are considered. Qualitative and quantitative morphological characters were evaluated for 32 accessions. Epidermal features were also studied for these accessions. The most variable morphological characters in the species delimitation were also determined. The varieties show significant variations in features as Awn status, Spike and spikelet length, Nerve number of Upper Glume, Lemma, Palea and Caryopsis length. Diagnostic features based on studied characters are identified and the varieties relationships are discussed.

Vulpia ciliata Dumort. ssp. ambigua (Le Gall) Stace & Auquier (Vulpia ambigua (Le Gall) More, Festuca ambigua Le Gall)

<i>Vulpia ciliata</i> Dumort. ssp. <i>ambigua</i> (Le Gall) Stace &amp; Auquier (<i>Vulpia ambigua</i> (Le Gall) More, <i>Festuca ambigua</i> Le Gall)

The Effect of Temperature on Seed Set and Seed Development in Detached Spikelets of Perennial Ryegrass (Lolium perenne L.)

In perennial ryegrass seed yield is low. Pollination, fertilization and early stages of seed development are critical periods for the realization of the yield potential. As intact plants are difficult to handle, we used detached spikelets to study effects of temperature and genotype on seed set and seed development.Plants of four cultivars were grown in pots. Just prior to flowering, spikelets were detached from the ears and put on water. After pollination, various spikelets of each plant were placed at different temperatures (14/14, 17/12 or 20/15°C). Seven days after pollination the percentage seed set and the length of the developing seeds (caryopses) were assessed. Only florets in the four basal positions were used.For each cultivar an analysis of variance for unbalanced data was carried out. There were highly significant difference among genotypes for seed set and caryopsis length. There was no evidence for genotypic variation for tolerance to low temperatures. Neither temperature nor floret position had an effect on seed set. The caryopsis length, however, increased with increasing temperature and basal florets produced longer caryopses than distal florets. The detached spikelets proved to be a useful experimental tool.

Temperature response of caryopsis elongation in relation to grain notching of rice.

Many researchers have reported that unsuitable ripening conditions such as low temperature, drought, shading, or fertilizer deficiency lead to grain notching of rice. In this study the mechanism of grain notching has been re-investigated from a view point of temperature effect on the caryopsis elongation. As the caryopsis of rice plant develops encased in floral glumes, the size and shape of the caryopsis are restricted by the floral glumes. However, it has been clarified that the caryopsis is capable of elongating longer than the floral glumes in general, and that the varieties in which the potential volume of the caryopsis far exceeds the capacity of floral glumes tend to produce such mulformed grains as notched or hull-cracked ones. In this study, for allowing full growth of the potential length of caryopsis (T1), upper parts of the floral glumes on two or three panicles of each plant were clipped off three days after anthesis, and these panicles were protected by parchment bags. The rest of panicles were kept untreated to determine the natural length of caryopsis (C1) which developed within the floral glumes. Seven rice cultivars (Table 1) were grown in pots and kept outdoors until heading time. Thereafter, they were divided into three lots and moved to phytotrons in which the temperature was maintained high (33/23°C), medium (28/18°C) or low (23/13°C), and grown under 30, 000 lux artificial light for 14 hours a day. Humidity was regulated to 70-80% and 85-95% during the light and dark period, respectively. As shown in Table 2, actual temperature inside the floral glumes and parchment bag was a little higher than ambient air temperature under illumination. Twenty-30 caryopses were sampled every, other day and measured to give growth curves for T1 and C1. Several growth parameters were estimated according to Robertson's equation. At maturity, rest of materials were harvested to examine seed fertility, notched grain percentage, and the size and shape of the caryopses. The result of present investigation has indicated followings : Although the growth late of C1 is lowered under low temperature, the maximum value of C1 is not different with temperature conditions, because C1 is restricted by the scope of floral glumes. As shown in Fig. 2, C1 reaches to its ceiling at 7 days (at high temp.), 9 days (at medium temp.) and 11 days (at low temp.) after anthesis. Under low temperature condition the growth rate of T1 is reduced, but because the growth duration is extended, the final length of T1 is the longest. Thus, the unbalance between the potential length of caryopsis and the capacity of floral glumes, or T1/C1 is higher under low temperature condition. Notched grain percentage increases under low temperature condition, and as shown in Fig. 3, it correlates with T1/C1 ratio. From these observations it may be concluded that under low temperature condition T1 shows excessive elongation, which leads to stronger unbalance between T1 and C1. When T1 is much longer than C1, the longitudinal development of caryopsis is restricted by floral glumes resulting in grain notching.

Selection Response and Correlated Response of Notched Grain Percentage and Unbalance between Potential Length of Caryopsis and Capacity of Froral Glumes in Rice : Unbalanced Growth in Floral Glumes and Caryopsis in Rice. VIII

Selection Response and Correlated Response of Notched Grain Percentage and Unbalance between Potential Length of Caryopsis and Capacity of Froral Glumes in Rice : Unbalanced Growth in Floral Glumes and Caryopsis in Rice. VIII

Mechanism of Grain Notching, and Variation for Notched Grain Frequency in Rice

Although the size and shape of the caryopsis in rice plants are determined by the capacity of the glume, the growth of the caryopsis and the floral glumes may be controlled by different genetic systems and thus they may have different developmental paths. Therefore, in varieties having potentially much longer caryopsis than the glume, the growth of the caryopsis may be affected by the glume leading to abnormal grain formation. One of such abnormal development of caryopsis is grain which is observcd with variable frequencies in some of the rice varieties. This investigation reveals an account of the mechanism of grain notching and the variation for notched grain frequency in rice. A total of 32 varieties and lines was grown in glasshouse as well as in field to investigate the varietal and environmental variation for the notched grain frequency and also the correlation of notched grain percentage with the unbalance between the length of the caryopsis and the glume. For allowing the caryopsis to grow freely, the top of the glume on one or two panicles in each of the plants was clipped off at two or three days after the anthesis. In the field, glume clipped panicles were protected by parchment paper bags. The length of glume-clipped caryopsis (T1) and untreated one (C1) were measured using ten caryopses randomly taken from each of the 6 plants in glasshouse and 20 plants in the field. T1/C1 ratio was calculated to indicate the degree of unbalance between the potential length of caryopsis (T1) and the longitudinal capacity of glume (C1). One hundred untreated caryopses from each of the plants were exarnined to determine the percentage of notched grain. The percentage was transformed into the degree of angle for the statistical analysis. Correlation between the T1/C1 ratio and the notched grain percentage was also analyzed. Varietal variation ranged from 0 to 90% for notcched grain and from 1.1 to 1.5 for T1/C1 ratio which indicated that the potential length of the caryopsis was 1.1 to 1.5times more than the longitudinal capacity of the glume. From these results, the materials used were classified into three groups: Group A, showing remarkably high, more than 80%, grain notching and high T1/C1 ratio in both the glasshouse and field conditions, group B, showing highly sensitive response of grain notching to the environmental conditions, and group C, showing mostly normal grains with low T1/C1 ratio. The glume-clipped caryopsis did not develop notched grain in all of the materials. Correlation between the glasshouse and field was high for C1 and T1, but it was rather low for notched grain percentage and thc T1/C1 ratio in some varital groups. Highly significant correlation between notched grain percentage and T1/C1 ratio (r=0.94) suggested that unbalance between the length of glume and caryopsis was the primary factor determinig the grain notching. From these studies, it may be concluded that, along with other factors, abnormal growth of the caryopsis restricted by the glume capacity results in notching of the caryopsis.

Investigation of Anthesis, Length of Caryopsis, Moisture Content, Seed Weight, Seed Shedding and Stripping-ripeness during Development and Ripening of aFestuca pratensisSeed Crop

Investigation of Anthesis, Length of Caryopsis, Moisture Content, Seed Weight, Seed Shedding and Stripping-ripeness during Development and Ripening of a<i>Festuca pratensis</i>Seed Crop