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Important Agronomic Traits (important + agronomic_trait)
Selected AbstractsOsEF3, a homologous gene of Arabidopsis ELF3, has pleiotropic effects in ricePLANT BIOLOGY, Issue 5 2009C. Fu Abstract Heading date is an important agronomic trait in rice. A rice mutant with a late heading date and no photoperiodic sensitivity in long or short day conditions was obtained from rice T-DNA insertion mutants in Zhonghua11 (ZH11). Through isolation and analysis of the flanking sequence of the T-NDA insertion site, the target sequence of insertion was obtained and found to locate in AP003296, the sequence accession number of rice chromosome 1 of RGP (http://rgp.dna.affrc.go.jp). The putative amino acid sequences of this target gene are homologous to the Arabidopsis protein ELF3 encoded by an early flowering gene. The rice target gene orthologous to Arabidopsis ELF3 is named OsEF3; this encodes a putative nematode responsive protein-like protein. OsEF3 has pleiotropic effects in rice that differ from the effects of Arabidopsis ELF3, which only affects biological rhythms. OsEF3 regulates heading date by influencing the BVG stage and does not affect photoperiodic sensitivity, which suggests that the OsEF3 gene may be involved in an autonomous pathway in rice. OsEF3 may affect root development and kilo-grain weight by delaying cell division or cell elongation. [source] Mutations of genes in synthesis of the carotenoid precursors of ABA lead to pre-harvest sprouting and photo-oxidation in riceTHE PLANT JOURNAL, Issue 2 2008Jun Fang Summary Pre-harvest sprouting (PHS) or vivipary in cereals is an important agronomic trait that results in significant economic loss. A considerable number of mutations that cause PHS have been identified in several species. However, relatively few viviparous mutants in rice (Oryza sativa L.) have been reported. To explore the mechanism of PHS in rice, we carried out an extensive genetic screening and identified 12 PHS mutants (phs). Based on their phenotypes, these phs mutants were classified into three groups. Here we characterize in detail one of these groups, which contains mutations in genes encoding major enzymes of the carotenoid biosynthesis pathway, including phytoene desaturase (OsPDS), ,-carotene desaturase (OsZDS), carotenoid isomerase (OsCRTISO) and lycopene , -cyclase (,-OsLCY), which are essential for the biosynthesis of carotenoid precursors of ABA. As expected, the amount of ABA was reduced in all four phs mutants compared with that in the wild type. Chlorophyll fluorescence analysis revealed the occurrence of photoinhibition in the photosystem and decreased capacity for eliminating excess energy by thermal dissipation. The greatly increased activities of reactive oxygen species (ROS) scavenging enzymes, and reduced photosystem (PS) II core proteins CP43, CP47 and D1 in leaves of the Oscrtiso/phs3-1mutant and OsLCY RNAi transgenic rice indicated that photo-oxidative damage occurred in PS II, consistent with the accumulation of ROS in these plants. These results suggest that the impairment of carotenoid biosynthesis causes photo-oxidation and ABA-deficiency phenotypes, of which the latter is a major factor controlling the PHS trait in rice. [source] Mass Production of Intergeneric Chromosomal Translocations through Pollen Irradiation of Triticum durum-Haynaldia villosa AmphiploidJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 11 2007Tong-De Bie Abstract Haynaldia villosa possesses a lot of important agronomic traits and has been a powerful gene resource for wheat improvement. However, only several wheat,H. villosa translocation lines have been reported so far. In this study, we attempted to develop an efficient method for inducing wheat,H. villosa chromosomal translocations. Triticum durum-Haynaldia villosa amphiploid pollen treated with 1 200 rad 60Co-,-rays was pollinated to Triticum aestivum cv. ,Chinese Spring'. Ninety-eight intergeneric translocated chromosomes between T. durum and H. villosa were detected by genomic in situ hybridization in 44 of 61 M1 plants, indicating a translocation occurrence frequency of 72.1%; much higher than ever reported. There were 26, 62 and 10 translocated chromosomes involving whole arm translocations, terminal translocations, and intercarlary translocations, respectively. Of the total 108 breakage-fusion events, 79 involved interstitial regions and 29 involved centric regions. The ratio of small segment terminal translocations (W·W-V) was much higher than that of large segment terminal translocations (W-V·V). All of the M1 plants were self-sterile, and their backcross progeny was all obtained with ,Chinese Spring' as pollen donors. Transmission analysis showed that most of the translocations were transmittable. This study provides a new strategy for rapid mass production of wheat-alien chromosomal translocations, especially terminal translocations that will be more significant for wheat improvement. [source] Variations in cadmium accumulation among rice cultivars and types and the selection of cultivars for reducing cadmium in the dietJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2005Jianguo Liu Abstract A pot trial was conducted with 52 rice cultivars of different types collected from different origins. The results showed that there were great differences in Cd concentrations in straw, brown rice and grain chaff among the rice cultivars grown in a soil containing a Cd concentration of 100 mg kg,1; the Cd concentrations in brown rice ranged from 0.22 to 2.86 mg kg,1. The great genotypic differences in Cd concentrations indicated that it is possible to lower the Cd content of rice through cultivar selection and breeding. Significant differences were found in the Cd concentrations of the rice types of Indica consanguinity and those of Japonica consanguinity, but not between their origins. There were significant correlations between straw and brown rice in Cd concentration and in the total amount of Cd accumulated. The distribution ratios of the Cd accumulated in brown rice to the total Cd accumulation in the above-ground rice plant varied greatly from 12.9 to 137.8 g kg,1, and there was significant correlation between the distribution ratios and Cd concentrations in brown rice. These indicated that Cd concentration in rice grain is governed by the transport of Cd from root to shoot and also from shoot to grain. Cd concentrations in brown rice also correlated significantly with some important agronomic traits, as well as with nitrogen concentrations, one of the most important criteria for rice quality. Copyright © 2004 Society of Chemical Industry [source] Mapping quantitative trait loci influencing panicle-related traits from Chinese common wild rice (Oryza rufipogon) using introgression linesPLANT BREEDING, Issue 6 2009X. Luo Abstract Panicle-related traits are important agronomic traits which directly associated with grain yield. In this study, we investigated quantitative trait loci (QTLs) associated with panicle-related traits using a set of 265 introgression lines (ILs) of common wild rice (Oryza rufipogon Griff.) in the background of Indica high-yielding cultivar Guichao 2 (O. sativa L.). A total of 39 QTLs associated with panicle-related traits including panicle length (PL), primary branch number (PBN), secondary branch number (SBN), spikelet number per panicle (SPP) and spikelet density (SD), were detected in the ILs with single-point analysis. The alleles of 20 QTLs derived from wild rice showed positive effects, and some QTLs, such as, QPl1b for PL, QPbn8 for PBN, QSd4 and QSd11b for SD and QSpp4 for SPP showed larger positive effects, providing good candidates and useful information for marker-aided improvement of yield potential of rice. Most of the QTLs controlling SPP, SBN and SD were located in cluster or closely linked on chromosomes, and the directions of their additive effects were consistent, which explained the genetic basis of significant correlations between their phenotypic characters. [source] | ||||||||||