Morphological characterization and inheritance of leaf hairiness in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) as analyzed by computer-aided phenotyping

Computer-aided image processing was used to study the morphology of leaf hairiness in the wheat cultivars Saratovskaya 29 and Golubka, as well as the introgressed line 102/00ⁱ of the cultivar Rodina carrying the gene for leaf hairiness introgressed from Aegilops speltoides. Morphological differences in leaf hairiness were detected and described in detail. The genetic control of hairiness was studied in two cultivars (Golubka and Saratovskaya 29) with similar hairiness patterns. Crossing these cultivars with the cultivar Rodina showed a monogenic inheritance in the cultivar Golubka and a digenic inheritance in the cultivar Saratovskaya 29, which has a denser hairiness. In the line 102/00ⁱ and the cultivar Golubka, the number of trichomes was positively correlated with their mean length. The cultivar Golubka was used as an example to study the effect of environmental conditions on the formation of hairiness. Plants of this cultivar were found to form more but shorter trichomes under field conditions.     

The role of chromosomes from homeologous group 5 in regulation of grain hardness and protein content in substitution lines of common wheat cultivar Saratovskaya 29

Genetic regulation of grain hardness and protein content in intervarietal substitution lines for chromosomes of homeologous group 5 was examined. Common wheat cultivar Saratovskaya 29 with high bread-backing properties served as the recipient. Donors of chromosomes 5A and 5D were 18 cultivars with variable traits examined, including high-protein cultivars (Atlas 66 and Diamant 2), and soft-grain cultivars (Ul’yanovka and Chinese Spring). Analysis of substitution lines pointed to a substantial effect of chromosome 5D on the regulation of both traits. It was demonstrated that as a result of intervarietal substitution for chromosome 5D from donor cultivars Ul’yanovka and Chinese Spring, the endosperm softness was increased compared to the recipient cultivar Saratovskaya 29. Substitution lines Saratovskaya 29/Atlas 66 5D and Saratovskaya 29/Diamant 2 5D were characterized by high grain protein content, as well as by high endosperm hardness. In addition, the line Saratovskaya 29/Novosibirskaya 67 5D, characterized by grain hardness higher than in Saratovskaya 29, was isolated. In the lines with intervarietal substitution of chromosome 5A, grain protein content was found to be lower than in recipient cultivar Saratovskaya 29.     

Characterization and density of trichomes on three common bean cultivars

Trichomes have been implicated as a mechanism which can confer resistance to both plant pests and drought. A study was conducted to provide information regarding genetic variability for trichome distribution and density among three diverse dry bean (Phaseolus vulgaris L.) cultivars, and to characterize the types of trichomes present among the cultivars. Trichomes on the leaf surfaces were micrographed with a scanning electron microscope (SEM) and counted using a stereomicroscope on both the abaxial and adaxial leaf surfaces of the cultivars ‘Bill Z’, ‘Pompadour Checa’ and ‘Diacol Calima’. Straight, hooked, and glandular trichomes were observed on the leaf surfaces of each cultivar. SEM micrographs are presented for the leaf surfaces of each cultivar and trichome type. The abaxial leaf surface had more straight trichomes than the adaxial leaf surface for ‘Pompadour Checa’ and ‘Diacol Calima’, however ‘Bill Z’ had more on the adaxial surface. The opposite relationship existed among the cultivars and leaf surfaces for the hooked trichomes.     

A cytogenetic study of the blue-grain line of the common wheat cultivar Saratovskaya 29

The chromosome composition of the blue-grain line i:S29Ba of the cultivar Saratovskaya 29 was identified by cytological, GISH, and microsatellite analyses and C-banding. It was found that common wheat chromosome 4B of the cultivar Saratovskaya 29 was substituted with the Agropyron elongatum Host. chromosome carrying the gene for blue grain (s:S294Ag(4B)) during the construction of this nearly isogenic line. The blue-grain line was tested for productivity. The substitution of total chromosome 4B of the cultivar Saratovskaya 29 by Ag. elongatum chromosome 4 did not significantly affect the spike productivity parameters and grain quality with the exception of spike length (plus effect), spike density, and vitreousness (minus effects). The blue-grain line with s:S294Ag(4B) can be used in further studies associated with chromosome engineering in cereals and wheat breeding.     

The effect of intercultivar substitution of wheat Triticum aestivum L. chromosomes on lipoxygenase activity and its correlation with the technological properties of flour

The effects of intercultivar substitution of individual chromosome pairs (except for 1B, 6D, and 7A) in the wheat cultivars Saratovskaya 29 and Janetzkis Probat, differing in quality, on specific lipoxygenase activity, the grain yield per spike, and the main technological properties of flour and dough were studied. It was demonstrated that the substitution of individual chromosomes of the recipient cultivar Saratovskaya 29 with the homologous chromosomes of the donor cultivar Janetzkis Probat caused significant changes in lipoxygenase activity and several other quality characteristics. The correlations between the lipoxygenase activity and the parameters of physical dough properties were determined. Three molecular forms of lipoxygenase (Lpx-1, Lpx-2, and Lpx-3), differing in the value of surface charge and enzymatic activity, were detected by native PAGE.     

The inheritance of endosperm storage proteins by the line of the Saratovskaya 29 cultivar of common wheat from its parental forms

We ran a comparative analysis of storage proteins (gliadins, high(HMW) and low-molecularweight (LMW) glutenins, puroindolines, and exogenous pest alpha-amylase inhibitors) in the Saratovskaya 29 cultivar line from the collection of a genetic engineering laboratory, its parental forms (Albidum 24 and Lutescens 55/11), and distant ancestors (Poltavka, Selivanovskiy Rusak, Sarroza, and tetraploid Beloturka). It was confirmed that the allelic states of storage proteins in the Gli-1, Gli-2 and Glu-1 loci originate from ancestral forms from the collection of the Vavilov Institute of Plant Industry. Moreover, new alleles were found in Lutescens 55/11 (Glu-A1a) and Selivanovskiy Rusak (Glu-B1b) cultivars from the collection of the Institute of Cytology and Genetics. A new allelic state, Ha, was observed in the loci of the Poltavka cultivar as a soft-grain cultivar, and the ha allele was found in the hard-grain Albidum 24 and Sarroza cultivars. It was found that the expression rate of exogenous pest alpha-amylase inhibitors in the Saratovskaya 29 cultivar line is lower than that of ancestral cultivars (Albidum 24, Sarroza, Poltavka, and Beloturka). Such inhibitors are absent in the paternal form Lutescens 55/11. A high expression rate of protein pest inhibitors for exogenous α-amylases and puroindolines was observed in the Poltavka cultivar. The allelic composition of Glu-1 loci was newly studied in the Sarroza cultivar, which has some promising features. The Saratovskaya 29 cultivar line, on the basis of which a wide range of diverse lines were created in the Institute of Cytology and Genetics, is isogenic for all of the studied traits.     

Influence of leaf trichomes on predatory mite (Typhlodromus pyri) abundance in grape varieties

Non-glandular leaf trichomes positively influence the abundance of many phytoseiid mites. We characterized the influence of grape leaf trichomes (domatia, hairs, and bristles) on Typhlodromus pyri Scheuten abundance over two years in a common garden planting of many grape varieties and 2 years of sampling in a commercial vineyard. In general, a lack of trichomes was associated with much lower predator numbers and in the case of Dechaunac, a cultivar with almost no trichomes, very few T. pyri were found. Phytoseiid abundance was best predicted by a model where domatia and hair had an additive effect (r (2) = 0.815). Over two years of sampling at a commercial vineyard there were T. pyri present on all of the 5 cultivars except Dechaunac. At the same time, European red mite prey were present on Dechaunac alone. These results suggest that on grape cultivars lacking leaf trichomes, T. pyri likely will not attain sufficient densities to provide biological control of European red mite, despite presence of the mite food source. The relationship between leaf trichomes and phytoseiid abundance that is observed at the scale of single vines in a garden planting appears to also be manifest at the scale of a commercial vineyard. Because persistence of predatory mites in or nearby the habitats of prey mites is important for effective mite biological control, leaf trichomes, through their influence on phytoseiid persistence, may be critical for successful mite biological control in some systems.     

Construction of immune lines with complex resistance to leaf rust and powdery mildew in common spring wheat cultivar Saratovskaya 29

Immune lines resistant both to leaf rust and to powdery mildew were constructed on the basis of common wheat cultivar Saratovskaya 29. Synthetic wheat Triticum timopheevii/Aegilops squarrosa (AAGGDD, 2n = 42) of Savov (Bulgaria) was used as a source of resistance genes. Using cytological analysis of BC2, we selected resistant plants (21") free from meiosis 1 (M1) defects. With these plants and continuous selection, BC8-BC9 immune lines were obtained. The lines were shown to carry new resistance genes differing from the known ones, and were proposed as donors of immunity to the diseases.     

The effect of intercultivar substitution of wheat <Emphasis Type="Italic">Triticum aestivum</Emphasis> L. chromosomes on lipoxygenase activity and its correlation with the technological properties of flour

The effects of intercultivar substitution of individual chromosome pairs (except for 1B, 6D, and 7A) in the wheat cultivars Saratovskaya 29 and Janetzkis Probat, differing in quality, on specific lipoxygenase activity, the grain yield per spike, and the main technological properties of flour and dough were studied. It was demonstrated that the substitution of individual chromosomes of the recipient cultivar Saratovskaya 29 with the homologous chromosomes of the donor cultivar Janetzkis Probat caused significant changes in lipoxygenase activity and several other quality characteristics. The correlations between the lipoxygenase activity and the parameters of physical dough properties were determined. Three molecular forms of lipoxygenase (Lpx-1, Lpx-2, and Lpx-3), differing in the value of surface charge and enzymatic activity, were detected by native PAGE.     

Characteristics of common wheat cultivars of West Siberia carrying the wheat-rye 1RS.1BL translocation

Using genomic in situ hybidization, among the common wheat cultivars produced in West Siberia (Siberian Research Institute of Agriculture, Omsk) with the involvement of the winter wheat cultivar Kavkaz carrying the wheat-rye 1RS.1BL translocation we identified three cultivars with this translocation: Omskaya 29, Omskaya 37, and Omskaya 38. The protein and crude gluten contents in the grain of these cultivars are equal to or exceed the levels observed in cultivars without the wheat-rye translocation. The common wheat cultivars carrying the wheat-rye translocation were evaluated in terms of resistance of plants reaching wax ripeness to leaf rust and powdery mildew in the natural field conditions. The cultivars Omskaya 37 and Omskaya 38 displayed a high field resistance to leaf rust and were resistant to a variable extent to powdery mildew. The cultivar Omskaya 29 was susceptible to leaf rust and powdery mildew pathogens. Importance of the selection direction and the role of the genetic background in developing common wheat cultivars carrying the wheat-rye translocation is discussed.     

Construction of Immune Lines with Complex Resistance to Leaf Rust and Powdery Mildew in Common Spring Wheat Cultivar Saratovskaya 29

Immune lines resistant both to leaf rust and to powdery mildew were constructed on the basis of common wheat cultivar Saratovskaya 29. Synthetic wheat Triticum timopheevii/Aegilops squarrosa (AAGGDD, 2n = 42) of Savov (Bulgaria) was used as a source of resistance genes. Using cytological analysis of BC₂, we selected resistant plants (21") free from meiosis 1 (M1) defects. With these plants and continuous selection, BC₈–BC₉ immune lines were obtained. The lines were shown to carry new resistance genes differing from the known ones, and were proposed as donors of immunity to the diseases.     

Assessing the influence of inflorescence traits on the susceptibility of grape to vine moths

In north‐eastern Italy during 1994–2006, studies were carried out on the susceptibility of grapevine cultivars to the first generations of the European vine moth [Lobesia botrana (Den. and Shiff.); Lep., Tortricidae] and the European grape berry moth [Eupoecilia ambiguella (Hb.); Lep., Cochylidae]. In five different years, the larval population density of both moth species and the larval age composition of L. botrana were recorded on 11 grapevine cultivars (Cabernet Sauvignon, Carmenère, Chardonnay, Pinot Gris, Merlot, Refosco dal Peduncolo Rosso, Rhine Riesling, Sauvignon Blanc, Terrano, Tocai Friulano, Verduzzo Friulano), grown in the same vineyard. The influence of inflorescence traits on these demographic parameters was also evaluated. On a 5‐year average, L. botrana significantly prevailed over E. ambiguella in nine of the 11 cultivars. Chardonnay and Pinot Gris were the most infested cultivars. Age composition of L. botrana larvae varied with cultivar type, being older on Chardonnay and Tocai Friulano than the other cultivars. Inflorescence earliness and hairiness explained the majority of the variability in cultivar susceptibility. In particular, the larval population level of the two vine moths was positively correlated with inflorescence earliness and negatively correlated with inflorescence hairiness. Lobesia botrana larval age composition was negatively correlated with inflorescence hairiness. Inflorescence earliness and hairiness could be used to predict in each grape‐growing area which cultivars are potentially more infested in the first generation. Inflorescences without pubescence, favouring an older age composition of first generation larvae, could induce an earlier second generation.     

Sink removal and leaf senescence in soybean : cultivar effects

Three cultivars of soybean (Glycine max [L.] Merr. cvs Harper, McCall, and Maple Amber) were grown in the field and kept continuously deflowered throughout the normal seedfill period. For all cultivars, deflowering led to delayed leaf abscission and a slower rate of chlorophyll loss. Compared to control plants, photosynthesis and ribulose 1,5-bis-phosphate carboxylase/oxygenase (Rubisco) level declined slightly faster for deflowered Harper, but for both McCall and Maple Amber, leaves of deflowered plants maintained approximately 20% of maximum photosynthesis and Rubisco level 1 month after control plants had senesced. Deflowering led to decreased leaf N remobilization and increased starch accumulation for all cultivars, but cultivars differed in that for McCall and Maple Amber, N and starch concentrations slowly but steadily declined over time whereas for Harper, N and starch concentrations remained essentially constant over time. SDS-PAGE of leaf proteins indicated that for all cultivars, deflowering led to accumulation of four polypeptides (80, 54, 29, and 27 kilodaltons). Western analysis using antisera prepared against the 29 and 27 kilodalton polypeptides verified that these polypeptides were the glycoproteins previously reported to accumulate in vacuoles of paraveinal mesophyll cells of depodded soybean plants. The results indicated that depending on the cultivar, sink removal can lead to either slightly faster or markedly slower loss of photosynthesis and Rubisco. This difference, however, was not associated with the ability to synthesize leaf storage proteins. For any particular cultivar, declines in chlorophyll, photosynthesis, and Rubisco were initiated at approximately the same time for control and deflowered plants. Thus, even though cultivars differed in rate of decay of photosynthetic rate and Rubisco level in response to sink removal, the initiation of leaf senescence was not influenced by presence or absence of developing fruits.     

Transmission of 5R Chromosomes via Gametes and Its Influence on Spring Bread Wheat Somatic Embryoidogenesis in Vitro

Transmission of chromosomes 5R via gametes and its effect on somatic embryoidogenesis have been studied with the use of the model 5R(5A) substitution line L2837 = L503/Secale cereale L., cultivar Saratovskaya 5//L503, where L503 is a cultivar of spring bread wheat. It has been found that the frequencies of transmission of univalent chromosomes 5R and 5A determined in experiments on F₁ reciprocal hybrids with cultivar Saratovskaya 29 do not reflect their frequencies in the self-pollinated offspring of F₁ hybrids; the frequency of transmission of chromosomes 5R and 5A depends on the genotypes of both the recipient cultivar and the donor rye cultivar; and the 5R(5A) substitution in cultivar L503 significantly increases the parameters of somatic embryoidogenesis in vitro in explants from inflorescences.     

Transmission of 5R chromosomes via gametes and its influence on spring bread wheat somatic embryoidogenesis in vitro

Transmission of chromosomes 5R and 5A via gametes and its effect on somatic embryoidogenesis have been studied with the use of the model 5R(5A) substitution line L2837 = L503/Secale cereale L., cultivar Saratovskaya 5/L503, where L503 is a cultivar of spring bread wheat. It has been found that the frequencies of transmission of univalent chromosomes 5R and 5A determined in experiments on F1 reciprocal hybrids with cultivar Saratovskaya 29 do not reflect their frequencies in the self-pollinated offspring of F1 hybrids; the frequency of transmission of chromosomes 5R and 5A depends on the genotypes of both the recipient cultivar and the donor rye cultivar; and the 5R(5A) substitution in cultivar L503 significantly increases the parameters of somatic embryoidogenesis in vitro in explants from inflorescences.     

Introgression of the reduced height gene Rht10 from the wheat cultivar Ai-bian 1 into the triticale genotype

A gene determining reduced height, Rht10, from the wheat cultivar Ai-Bian 1 was introgressed into the triticale genotype. Initially, Ai-Bian 1 was crossed with the wheat cultivar Chinese Spring (CS), a carrier of Kr genes, to overcome the uncrossability of this cultivar with rye. Amphidiploids were produced by hybridizing the F2 (CS x Ai-Bian 1) plants displaying reduced height (at the level of Ai-Bian 1) with rye. Free pollination of F1 (F2 of CS x Ai-Bian 1) x Saratovskaya 7 with triticale pollen gave fertile viable hybrids; the majority of hybrids were phenotypically closer to octoploid triticale; however, the variants intermediate between octo- and hexaploids were also present. The height of amphidiploids varied from 40 to 90 cm, and the grain yield per spike amounted on the average to 11.7--24.7 grains, which exceeded essentially this value in F1 plants.     

Molecular mapping of Verticillium wilt resistance QTL clustered on chromosomes D7 and D9 in upland cotton

Verticillium wilt is a destructive disease with international consequences for cotton production. Breeding broad-spectrum resistant cultivars is considered to be one of the most effective means for reducing crop losses. A resistant cotton cultivar, 60182, was crossed with a susceptible cultivar, Jun-mian 1, to identify markers for Verticillium resistance genes and validate the mode of its inheritance. Genetic segregation analysis for Verticillium wilt resistance was evaluated based upon infected leaf percentage in the seedling stage using major gene-polygene mixed inheritance models and joint analysis of P₁, P₂, F₁, B₁, B₂ and F₂ populations obtained from the cultivar cross. We found that resis-tance of upland cotton cultivar 60182 to isolates BP2, VD8 and T9, and their isoconcentration mixture was controlled by two major genes with additive-dominance-epistatic effects, and the inheritance of the major gene was dominant. Furthermore, a genetic linkage map was constructed using F₂ segregating population and resistance phenotypic data were obtained using F_2︰3 families inoculated with different isolates and detected in different developmental stages. The genetic linkage map with 139 loci was comprised of 31 linkage groups covering 1165 cM, with an average distance of 8.38 cM between two markers, or 25.89% of the cotton genome length. From 60182, we found 4 QTL on chromosome D7 and 4 QTL on D9 for BP2, 5 QTL on D7 and 9 QTL on D9 for VD8, 4 QTL on D7 and 5 QTL on D9 for T9 and 3 QTL on D7 and 7 QTL on D7 for mixed pathogens. The QTL mapping results revealed that QTL clusters with high contribution rates were screened simultaneously on chromosomes D9 and D7 by multiple interval mapping (CIM), whether from resistance phenotypic data from different developmental stages or for different isolates. The result is consistent with the genetic model of two major genes in 60182 and suggests broad-spectrum resistance to both defoliating isolates of V. dahliae and nondefoliating iso-lates. The markers associated with resistance QTL may facilitate the use of Verticillium wilt resistance genes in improving breeding programs for cotton.     

Introgression of a leaf rust resistance gene from <Emphasis Type="Italic">Aegilops caudata</Emphasis> to bread wheat

Rusts are the most important biotic constraints limiting wheat productivity worldwide. Deployment of cultivars with broad spectrum rust resistance is the only environmentally viable option to combat these diseases. Identification and introgression of novel sources of resistance is a continuous process to combat the ever evolving pathogens. The germplasm of nonprogenitor Aegilops species with substantial amount of variability has been exploited to a limited extent. In the present investigation introgression, inheritance and molecular mapping of a leaf rust resistance gene of Ae. caudata (CC) acc. pau3556 in cultivated wheat were undertaken. An F(2) population derived from the cross of Triticum aestivum cv. WL711 - Ae. caudata introgression line T291-2 with wheat cultivar PBW343 segregated for a single dominant leaf rust resistance gene at the seedling and adult plant stages. Progeny testing in F(3) confirmed the introgression of a single gene for leaf rust resistance. Bulked segregant analysis using polymorphic D-genome-specific SSR markers and the cosegregation of the 5DS anchored markers (Xcfd18, Xcfd78, Xfd81 and Xcfd189) with the rust resistance in the F(2) population mapped the leaf rust resistance gene (LrAC) on the short arm of wheat chromosome 5D. Genetic complementation and the linked molecular markers revealed that LrAC is a novel homoeoallele of an orthologue Lr57 already introgressed from the 5M chromosome of Ae. geniculata on 5DS of wheat.     

Association of the Production of Phenylpropanoid Compounds at the Infection Sites of Corynespora cassiicola with Soybean Resistance against Target Spot

This study investigated, at the microscopic level, whether the differential defence responses of soybean cultivars that are resistant (Fundacep 59) and susceptible (TMG 132) to target spot, caused by Corynespora cassiicola, could be associated with an increase in the production of phenolics, flavonoids and lignin at the infection sites. Many larger necrotic lesions with yellow halos were noticed on the leaves of plants from cultivar TMG 132, in contrast to the leaves of plants from cultivar Fundacep 59. Necrotic lesions also developed on the petioles of leaves of plants from cultivar TMG 132, while on the petioles and veins of leaves of plants from cultivar Fundacep 59, the lesions were of purple colour. The growth of fungal hyphae was reduced on the leaves of plants from cultivar Fundacep 59, and an apparently high density of trichomes was found in comparison with the leaves of plants from cultivar TMG 132. An appressorium‐like structure was produced at one or both extremities of the conidium of C. cassiicola, preferentially at the major and minor veins on the adaxial leaf surface of plants from both cultivars. Most cells on the leaves of plants from cultivar Fundacep 59 reacted against C. cassiicola infection by accumulating phenolic‐like compounds, which contributed to the death of many fungal hyphae and a greater maintenance of cell integrity. In contrast, fungal hyphae grew without any impedance in the leaf cells of plants from cultivar TMG 132, which was associated with signs of intense leaf tissue disorganization. Stronger autofluorescence and deposition of lignin and flavonoids were found in the cells of leaves of plants from cultivar Fundacep 59, in contrast to cultivar TMG 132. It can be concluded that soybean resistance to target spot is probably dependent on the activation of the phenylpropanoid pathway.     

Extraction of quantitative characteristics describing wheat leaf pubescence with a novel image-processing technique

Leaf pubescence (hairiness) in wheat plays an important biological role in adaptation to the environment. However, this trait has always been methodologically difficult to phenotype. An important step forward has been taken with the use of computer technologies. Computer analysis of a photomicrograph of a transverse fold line of a leaf is proposed for quantitative evaluation of wheat leaf pubescence. The image-processing algorithm is implemented in the LHDetect2 software program accessible as a Web service at http://wheatdb.org/lhdetect2. The results demonstrate that the proposed method is rapid, adequately assesses leaf pubescence density and the length distribution of trichomes and the data obtained using this method are significantly correlated with the density of trichomes on the leaf surface. Thus, the proposed method is efficient for high-throughput analysis of leaf pubescence morphology in cereal genetic collections and mapping populations.