A PCR-based Genotyping Method to Distinguish Between Wild-type and Ornamental Varieties of Imperata cylindrica

Wild-type I. cylindrica (cogongrass) is one of the top ten worst invasive plants in the world, negatively impacting agricultural and natural resources in 73 different countries throughout Africa, Asia, Europe, New Zealand, Oceania and the Americas1-2. Cogongrass forms rapidly-spreading, monodominant stands that displace a large variety of native plant species and in turn threaten the native animals that depend on the displaced native plant species for forage and shelter. To add to the problem, an ornamental variety [I. cylindrica var. koenigii (Retzius)] is widely marketed under the names of Imperata cylindrica 'Rubra', Red Baron, and Japanese blood grass (JBG). This variety is putatively sterile and noninvasive and is considered a desirable ornamental for its red-colored leaves. However, under the correct conditions, JBG can produce viable seed (Carol Holko, 2009 personal communication) and can revert to a green invasive form that is often indistinguishable from cogongrass as it takes on the distinguishing characteristics of the wild-type invasive variety4 (Figure 1). This makes identification using morphology a difficult task even for well-trained plant taxonomists. Reversion of JBG to an aggressive green phenotype is also not a rare occurrence. Using sequence comparisons of coding and variable regions in both nuclear and chloroplast DNA, we have confirmed that JBG has reverted to the green invasive within the states of Maryland, South Carolina, and Missouri. JBG has been sold and planted in just about every state in the continental U.S. where there is not an active cogongrass infestation. The extent of the revert problem in not well understood because reverted plants are undocumented and often destroyed

Application of aspen MADS-box genes to alter reproduction and development in trees

The present invention provides compositions and methods for producing a transgenic plant that exhibits altered characteristics resulting from over expression or under expression of a novel polypeptide PtM3 or its homolog PtM4. The altered characteristics resulting from over-expression include at least one of the ability to convert axillary mer- istem to floral meristem; to accelerate flowering i.e., early flowering; to increase fruit production; to increase nut production; to increase seed output; to increase branching; to increase flower production; to increase fruit yield; to increase flower yield and a combination thereof. The altered characteristics resulting from suppressed expression include at least one of complete sterility; partial sterility (sterility of only one sex of a bisexual plant); reduced pollen production; decreased flowering; increased biomass and combinations thereof. Furthermore, once the transgenic plant is sterile, additional exogenous sequences may be incorporated into the sterile plant genome, resulting in other desired plant characteristics. Related promoter, gene constructs, methods, antibodies and kits are also provided.https://digitalcommons.mtu.edu/patents/1041/thumbnail.jp

Use of Foliar Chemical Treatments to Induce Disease Resistance in Rhododendrons Inoculated with Phytophthora ramorum

A field study was conducted at the National Ornamental Research Site at Dominican University California (NORS-DUC). The study goal was to evaluate three chemical inducers applied as foliar treatments for controlling Phytophthora ramorum, on Rhododendron x ‘Cunningham’s White’ nursery plants. The inducers were chlorine dioxide (ElectroBiocide), hydrogen peroxide (OxiDate 2.0), and acibenzolar-s methyl (Actigard). Water samples from the electrostatic sprayer were measured for three physicochemical water properties. Visual assessment of plant foliage, based on the Horsfall- Barratt scale, was conducted at three and five months after chemical treatments. Foliar fluorescence (Fv/Fm) was measured over three dates. The success of P. ramorum inoculations were determined using qPCR methods. Visual assessment across both months showed no signs of P. ramorum infection or chemical injury symptoms. However, P. ramorum infection vis-à-vis qPCR analysis was confirmed. The September Fv/Fm results revealed that all the chemical inducer treatments were equivalent to the water treatment, except for Actigard. The qPCR results were in general agreement with the Fv/Fm results indicating that the rhododendrons were successfully inoculated with P. ramorum but were non-symptomatic. The electrostatic sprayer ionized the water droplets, resulting in increased Fv/Fm values for the water treatments 90 days after application. There was a three-month delay in fluorescence responses to the most effective chemical applications, indicating that woody plants may need to be monitored over the long term to determine accurate responses to foliar treatments

Global agricultural intensification during climate change: a role for genomics

Agriculture is now facing the ‘perfect storm’ of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic-assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change

Application of genomics-assisted breeding for generation of climate resilient crops: Progress and prospects

Climate change affects agricultural productivity worldwide. Increased prices of food commodities are the initial indication of drastic edible yield loss, which is expected to increase further due to global warming. This situation has compelled plant scientists to develop climate change-resilient crops, which can withstand broad-spectrum stresses such as drought, heat, cold, salinity, flood, submergence and pests, thus helping to deliver increased productivity. Genomics appears to be a promising tool for deciphering the stress responsiveness of crop species with adaptation traits or in wild relatives toward identifying underlying genes, alleles or quantitative trait loci. Molecular breeding approaches have proven helpful in enhancing the stress adaptation of crop plants, and recent advances in high-throughput sequencing and phenotyping platforms have transformed molecular breeding to genomics-assisted breeding (GAB). In view of this, the present review elaborates the progress and prospects of GAB for improving climate change resilience in crops, which is likely to play an ever increasing role in the effort to ensure global food security

Molecular biology of floral scent evolution: Characterization of linalool synthase (LIS) in diverse species.

Flowers of Clarkia breweri as well as many other species emit linalool, an acyclic monoterpene, as part of the scent volatile mixture that attracts pollinators. Surprisingly, it is not uncommon for scented species to evolve from nonscented species. C. breweri, for example, has evolved relatively recently from an extant nonscented species, Clarkia concinna. Despite the importance of floral scent to the survival of many angiosperms, none of the enzymes or genes involved in the production of any floral scent compound had been characterized at the start of this project. Hence, this project focuses on one such enzyme, linalool synthase (LIS), and examines the general question of how nonscented species can give rise to scented species thereby changing the plant's specific pollinator. A cDNA of LIS1, the gene encoding LIS in C. breweri, was isolated, and subsequent Northern blots, in situ hybridizations, and Western blots showed that the strong floral scent of C. breweri is the result of (1) upregulation of a preexisting C. concinna LIS gene at the level of nucleic acid and (2) expansion of the types of tissues that express this gene. Organelle preparations treated with proteinase K, subcellular fractionations, and immunogold localizations together show that leucoplasts are the subcellular location of LIS1. However, although the N-terminus of LIS has the characteristics of a plastid targeting sequence, only a maximum of 8 amino acids are cleaved from the mature protein. Thus, LIS1 appears to have a non-cleavable plastid targeting sequence. LIS and LIS-like (LSL) genes isolated from C. breweri, C. concinna, Oenothera arizonica, and Arabidopsis thaliana encode proteins that are 40-96% identical to each other and have 11 introns in identical positions. Comparisons of these sequences with the sequences of other terpene synthases show that LIS and LSL are composite genes which evolved from a cross-over event between two different types of terpene synthases. Although known to occur, this is the first time such domain swapping has been demonstrated in terpene synthases. This study shows how scent can evolve in a relatively simple way through up-regulation of pre-existing genes and suggests that the combined evolutionary mechanisms of duplication, followed by divergence and/or domain swapping, may explain the extraordinarily large diversity of proteins found in the plant terpene synthase family.Ph.D.BiochemistryBiological SciencesBotanyGeneticsMolecular biologyPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/131184/2/9840518.pd

Handbook of molecular and cellular methods in biology and medicine, 2nd ed./ Edit.: Leland J. Cseke

580 hal.: ill.; 26 cm

Handbook of molecular and cellular methods in biology and medicine, 2nd ed./ Edit.: Leland J. Cseke

580 hal.: ill.; 26 cm