Polymorphisms of α-amylase activity in barley landraces and cultivars from China

Summary -Amylase activity was assayed by measuring reducing power equivalent for 80 accessions of cultivated barley, Hordeum vulgare L., representing major barley growing areas of China. Replications were applied at two different levels of the experiment and enzyme activity was assayed on four consecutive days starting on the 6th day after germination. The area under the curve formed by connecting the four data points was integrated as the measurement of -amylase activity. The results established that there was extensive variation in -amylase activity in cultivated barley; about three-fold difference existed among accessions assayed. Comparisons were also made between six- and two-rowed, and between covered and naked barleys. The results showed that high -amylase activity was not necessarily associated with six-rowed type, and that covered barleys were slightly higher in -amylase activity than naked ones.     

Expression of late maturity α-amylase in wheat containing gibberellic acid insensitivity genes

Summary Two wheat cultivars, Spica and Lerma 52, which consistently produce high levels of -amylase during the later stages of grain development (late maturity -amylase), were crossed with a set of four near-isogenic lines carrying the tall (rht) allele or one of the dwarfing genes Rht1, Rht2 or Rht3 (GA-insensitive alleles). The F₁ and F₂ populations were developed and analysed for grain -amylase and plant height. The Rht3 gene exhibited the strongest influence on plant height and strongly inhibited new -amylase synthesis during the later part of grain ripening. By comparison, Rht1 and Rht2 had a less pronounced effect but still significantly reduced the expression of late maturity -amylase. These observations suggest that gibberellic acid is involved either directly or indirectly in this phenomenon. The implications of the effect of dwarfing genes on expression of late maturity -amylase are discussed in relation to cultivar improvement and to the identification and control of high -amylase germplasm.     

Inheritance of late maturity α-amylase in wheat

Summary Two wheat cultivars that consistently show high levels of grain -amylase at harvest ripeness, in the absence of preharvest sprouting, were crossed with a control, low -amylase cultivar, and F₁, F₂ and BC₁ populations were developed. Grain of these populations was analysed for -amylase activity at harvest ripeness. Distribution and segregation patterns were consistent with control at a single locus with high -amylase the recessive allele. This mode of inheritance would make it extremely difficult to differentiate homozygous low -amylase lines from heterozygotes (low -amylase phenotype but carriers of high -amylase) and has important implications for wheat breeders. High -amylase, termed late maturity -amylase, was not linked with the awned inhibitor gene, B2, located on the long arm of chromsome 6B.     

Gibberellic acid effects on germination and α-amylase activity of winter wheats

Summary Sensitivity to GA in non-Gai genome winter wheat (Triticum aestivum L.) cultivars was investigated to determine magnitude of variation of the trait, its association with other traits, and effects of geographical location of production. -Amylase enzyme activity was measured before and after treatment with gibberellic acid in 18 cultivars grown at one location and in five cultivars grown at six locations. Dye-labeled starch and agar-starch media procedures were used for the first and second experiments, respectively. -Amylase activity differed significantly among the 18 cultivars after germination in water, germination in GA, and in absolute and relative sensitivity to GA. Cultivars that reacted similarly to GA had some common ancestors in their pedigrees, and -amylase activity and sensitivity to GA were significantly negatively associated with seed weight. -Amylase activity differed between tall and semi-dwarf cultivars in the second experiment, but not in the first experiment. The magnitude of variation in -amylase activity and its relationship to preharvest sprouting susceptibility of the cultivars suggested that the trait can be modified to improve seed dormancy. Significant interactions between cultivar responses to GA and geographical location of grain production suggested that selection should be carried out in several environments.Contribution no. 81-162-j, Department of Agronomy, Kansas State University, Manhattan KS 66506, USA.     

α-Tomatine and other steroidal glycoalkaloids in fruits of tomato lines resistant to the glasshouse whitefly (Trialeurodes vaporariorum Westw.)

Summary The total steroidal alkaloid compositions of the mature-harvested fruits of the tomato cultivar Allround (Lycopersicon esculentum), of the species L. hirsutum glabratum, resistant to the glasshouse whitefly (Trialeurodes vaporariorum), and of four resistant lines were determined by capillary gas chromatography. The contents of -tomatine in the red-ripe fruits of Allround and in those of the lines were low (5 mg/kg fresh weight). The green-mature fruits of the wild species had a high content (3390 mg/kg fresh weight) of -tomatine. The total alkaloid profiles of Allround and of the lines were similar. Comparison of flame ionisation detector response with thermoionic detector response indicated that in addition to tomatidine, the aglycone of -tomatine, a small amount of one other steroidal alkaloid might be present in Allround and in the lines. The wild species contained five compounds which possibly are steroidal alkaloids.The safety level of -tomatine in tomatoes is discussed. It was concluded that, in respect of the glycoalkaloids of the mature-harvested fruits, the resistant tomato breeding lines are as safe for human cosumption as the standard cultivar.     

Genetic analysis of hexaploid wheat,Triticum aestivum using intervarietal chromosome substitution lines—protein content and grain weight

Summary The 21 intervarietal chromosome substitution lines of the cultivar Hope in Chinese Spring were used to analyse the genetic differences between the two cultivars Hope and Chinese Spring in grain protein content and grain weight.Only one chromosome of Hope, 5D, significantly influenced grain protein content of Chinese Spring. Its influence was of only minor effect and was to decrease protein content expression of Chinese Spring. It has been postulated that the genetic control of protein content, in this instance, is most likely due to many genes each of small effect.Five chromosomes of Hope influenced the 1000 grain weight value of normal Chinese Spring, all increasing its expression. Chromosomes 1A, 4A and 5B were of major effect and 3A and 6A of comparatively minor effect. A minimal estimate of five genes determines the difference in grain size between these cultivars. The possible evolutionary significance of the contribution of the A genome of bread wheat to grain size determination is discussed. On the basis of certain findings of this study, proposals are made for breeding for increased grain size in hexaploid wheat.     

Lilium x ‘Black Beauty’—a potential bridging hybrid in Lilium

Summary Lilium Black Beauty, a rare intersectional hybrid previously reported sterile, was re-examined for pollen and ovule fertility. No pollen tubes were detected following incubation of styles pollinated with Black Beauty pollen. However, embryos varying in size from small globular to long boat-shaped and only rarely associated with endosperm, were found in 0.1–1.0% of the ovules in Black Beauty pistils pollinated with Oriental or Aurelian division lilies. Aseptic extraction and culture of these embryos on a nutritive medium resulted in growth, germination, and plantlets. It is apparent that with embryo culture, Black Beauty has unique value as a species bridge in that it accepts pollen of both Oriental and Aurelian lilies, two of the major commercial lily divisions.Scientific Journal Series Paper Number 9197 of the Minnesota Agricultural Experimental Station.     

Effect of genetic blends of dry beans (Phaseolus vulgaris) of different Plant architecture on apothecia production of Sclerotinia sclerotiorum and white mold infection

Summary The determinate Phaseolus vulgaris L. cvs Dark Red Kidney Charlevoix, and near-isogenic Great Northern Nebraska 1 were grown in blends with the indeterminate GN Nebraska 1 in white mold (Sclerotinia sclerotiorum) disease field nurseries. A critical difference between Charlevoix and indeterminate GN Nebraska 1 is that the latter has a greater leaf area closer to the soil surface, and this is associated with increased numbers of apothecia beneath the canopy and higher disease severity. White mold infection and apothecia number/m² beneath the canopy of the blends containing Charlevoix were significantly reduced in comparison with the severely infected, homogeneous, indeterminate GN Nebraska 1. A reduction of white mold infection for the indeterminate GN Nebraska 1 was not observed in blends grown under severe or moderate white mold incidence, but did occur under slight incidence in blends containing 65% and 75% Charlevoix.No significant difference for seed yield occurred between the blends and homogeneous cultivars planted in four experiments under severe, moderate, slight and zero white mold incidence, respectively, except in Experiment 1 under moderate white mold incidence, the blend of 50% indeterminate GN Nebraska 1 and 50% Charlevoix exceeded the yield of the indeterminate GN Nebraska 1. Mean weight of white (GN Nebraska 1) and red seed (Charlevoix) increased and decreased, respectively, in some blends due to the more vigorous growth of the indeterminate GN Nebraska 1.Published as Paper No. 5341, Journal Series, Nebraska Agric. Exp.t Station. Research was conducted un under Project 20–3.     

Genetics and histology of powdery mildew resistance in apple

Summary Eight scab-resistant cultivars and selections along with eight commercial apple cultivars were evaluated for powdery mildew resistance in greenhouse and nursery tests. Dayton, Liberty, Delicious and Tolman Sweet were rated moderately resistant to infection in both greenhouse and nursery tests. Segregation of seedlings among 14 progenies for mildew reaction indicated that mildew resistance is polygenically controlled in this material with additive gene effects. Recovery of mildew resistant seedlings from crosses involving a scab-resistant parent(s) suggested that this material can be useful in developing scab- and mildew-resistant apple cultivars. Histological investigations were conducted to describe mildew symptoms of infected leaves.     

On defining a winter wheat

Summary An international survey of wheat breeders and scientists was conducted to determine whether there was a common understanding of the term winter wheat. Response to photoperiod was mentioned by only seven of the 30 survey respondents. It was consequently suggested that it be excluded from any definition. Response to vernalization was mentioned by 28 of the 30 respondents. However, there was considerable variation in the method of quantifying this response and the degree of response necessary for wheat to be called winter. It was concluded that the only objective and internationally consistent definition of winter wheat was a genetic definition based on the complement of Vrn genes a wheat possesses. Varieties not possessing any of the dominant Vrn alleles appear to take a distinctively longer and more variable time to head when grown under non-vernalizing, long day conditions. These are genetically winter wheats.     

Diallel analysis of yield components of snap beans exposed to two temperature stress environments

Ten snap beans (Barrier, Brio, Carson, Cornell 502, CT 70, HB 1880, Hystyle, Labrador, Opus and Venture) were selected for differential temperature tolerance and used as parents in a complete diallel mating design. The 45 F₁ hybrid lines (with reciprocals) and parents were screened at 32 C day/28 C night, and in a separate experiment, 16 C day/10 C night, during reproductive development in replicated controlled environments. Variation for yield under temperature treatments was observed among parents and hybrids, with certain hybrids exceeding parental performance. Significant (P 0.0001) general combining ability (GCA), and significant (P 0.05) specific combining ability (SCA) were observed for yield components including pod number, seed number, and seeds per pod. There was evidence that pod number and seeds per pod under temperature stress are under separate genetic control. Reciprocal effects and heterosis were not significant. GCA could not be predicted from parental performance. The breeding line Cornell 502 had the highest GCA under high temperature, and the cultivar Brio had the highest GCA under low temperature. The cross Brio × Venture was high yielding in both temperature treatments. Heat tolerance and chilling tolerance were associated in certain parents and hybrids. However, performance under high and low temperature treatments was not generally correlated in the parents and hybrids, indicating that these traits should be selected separately.     

Molecular and biological studies on male sterile cytoplasm in Cruciferae. II. The origin of Ogura male sterile cytoplasm inferred from the segregation pattern of male sterility in the F1 progeny of wild and cultivated radishes (Raphanus sativus L.)

Summary To determine the origin of Ogura male sterile cytoplasm in radish (Raphanus sativus L.), wild and cultivated radishes were crossed. Three types of progeny resulted from the F₁ hybrids between the wild radish from Kushikino with Ogura-type mtDNA and the cultivars (Uchiki-Gensuke or Comet). The segregation patterns of the male sterility were compared with those of Ogura cytoplasm. The male sterility induced in the F₁ hybrid was maintained by crossing with Uchiki-Gensuke, that maintains Ogura male sterility. In the two types of progeny, in which Comet (a restorer of Ogura cytoplasm) was used as one of the parents, both fertile and sterile plants segregated at the predicted ratio on the assumption that a single dominant fertility restoring gene exists in the restorer. From these results, we concluded that the Ogura cytoplasm is identical to that of the wild radish, and the former originated in a population of Japanese wild radish.     

Limited but specific variations of seed storage proteins in Japanese common wheat (Triticum aestivum L.)

The electrophoretic banding patterns ofgliadin in common wheat lines derived fromJapan were determined byacid-polyacrylamide gel electrophoresis. For the 107 wheat lines used in our study,27 different patterns were identified, 13corresponding to the -gliadin, 8 tothe , -gliadin and 6 to the-gliadin. The gliadin patterns ofJapanese wheat cultivars and landracesgreatly differed from the patterns of wheatlines from other countries, and thevariation seen in wheat lines from Japanwas limited to 46 patterns. Sevencollection or breeding areas in Japanshowed different frequencies in theirgliadin patterns. Combining the gliadinpatterns with high molecular weightglutenin subunit compositions, 67combinations were observed. One gliadinpattern consisting of -gliadinpattern F, , -gliadinpattern H and -gliadin pattern Dwas frequently found in many Japanese wheatlines, though the other patterns werelimited to only one or two wheat lines.     

Accumulating polygenes for partial resistance in barley to barley leaf rust,Puccinia hordei. I. Selection for increased latent periods

Summary The barley cultivar Cebaba Capa was crossed to the cultivar L94, which is assumed to carry no genes for increased latent periods, and Vada, which is assumed to carry five to six minor genes for a longer latent period (LP). In the F2 selection was carried out for short and long LP's in the young flag leaves to Puccinia hordei in both crosses. In the F3, F4 and F5 the selection for short as well as for long LP continued by selecting the extreme plants in the extreme lines, a typical pedigree selection approach.The LP's are given relative to those of L94, set at 100 and of Vada, set at 185. From the cross with L94 homogeneous lines were obtained with relative LP's of 100 and of 220. From the cross with Vada the extreme lines had LP's of 135 and around or even beyond 300.Cebaba Capa is thought to carry four to six minor genes with an average gene effect slightly larger than those of the five to six minor genes in Vada. From the four to six minor genes one or two may be identical to or closely linked with minor genes of Vada, the others appeared to be different. In the lines with LP's of close to 300 or even more the number of minor genes accumulated is thought to be in the order of eight or nine. These gene number estimates are based on independent assortment. If linkage occurs the number of genes involved may be larger.Because of the high correlation between LP in the young flag leaf and the partial resistance in the field the selected lines are assumed to have a partial resistance to barley leaf rust far beyond that of Vada, which represents almost the highest level of partial resistance in European cultivars.     

Inheritance of aroma in rice

Summary Inheritance of an aroma was worked out in crosses between Brimful from Nepal as an aromatic rice and leading Japanese varieties Koshihikari and Nipponbare as non-aromatic ones. The F₂ pattern of segregation for aroma to non-aroma was 3:13 indicating one dose gene for aroma and one dose inhibitor gene in two crosses. This ratio was confirmed by genetic behavior of F₃ populations.     

The grain yield of uniculm barley (Hordeum vulgare L.) in two contrasting environments

Summary Four six-rowed uniculm lines of spring barley were grown in two yield trials at different sowing densities. One trial was grown on light sandy soil in 1990. The second trial was grown on clay soil in 1991 and included the two-rowed, tillering cultivar Golf. In the trial on sandy soil, the grain yield of the uniculm lines approached that of Golf grown in an adjacent trial, but in 1991 when the growing conditions were more favourable, Golf yielded significantly more than the uniculm lines. Uniculm lines apparently perform relatively better under marginal growing conditions than in high yielding environments.The uniculm lines do not conform to the ideotype proposed for wheat by Donald (1968) but the results show that a drastic change in plant type need not to imply a large drop in grain yield.     

Embryo development in two barley genotypes after self pollination and pollination with Hordeum bulbosum L.

Summary Embryo development in vivo was compared in the two barley genotypes VK 16032 and Vogelsanger Gold after self pollination and after pollination with H. bulbosum. Embryo growth in VK 16032 after crossing with H. bulbosum showed a similar growth pattern to that of the self pollinated embryos, although the size increase was smaller. The hybrid embryos continued to grow until day 18 after pollination. The embryos from the cross between Vogelsanger Gold and H. bulbosum ceased to grow 8 days after pollination. Arrested embryo growth with subsequent abortion in Vogelsanger Gold was associated with a very early depletion and break down of the endosperm. Use of barley genotypes less sensitive to the genomic disturbances after crossing with H. bulbosum in combination with genotypes like Vogelsanger Gold is recommended in haploid breeding work.     

Inheritance of resistance to powdery mildew (Erysiphe graminis f. sp. hordei) in eleven primitive barley varieties

The inheritance of the powdery mildew resistance of eleven primitive barley varieties was investigated. crosses with varieties with identified resistance genes revealed that at least three different genes are present in a group of six genotypes from Greece (Hor736, Hor847, Hor878, Hor1159, Hor1379 and Hor1873) and one from Turkey (Hor1188). One dominant gene is common to these seve genotypes and in the Greek accessions a second gene is present. The expression of this second gene was respectively dominant in the crosses with Hor736 and Hor1159, recessive in the crosses with Hor878 and Hor1873, and depended on the employed powdery mildew isolate in the crosses with Hor847 and Hor1379. The detected genes differ from the resistance genes of the crossing partners, viz. Ml-al2, Ml-(Ab), Ml-(CP) and Ml-(1402). The accessions from China (Hor824 and Hor4021) each possess two resistance genes which differ from Ml-a12, Ml-(La) and Ml-(CP). The major gene is common to both accessions and is either identical, allelic or closely linked to a gene in the variety Nigrate. The Columbian accession Hor1894 possesses one resistance gene linked to a resistance gene in Nigrate but this gene differs from the Ml-a locus. The variety Palestine (Hor3997) possesses two resistance genes of which one is allelic or closely linked to Ml-(at).     

Effect of ploidy on stomatal and other quantitative traits in plantain and banana hybrids

Summary Ploidy polymorphism occurs in the hybrid offspring derived from interspecific crosses between triploid plantains (Musa spp. AAB group) and diploid bananas (M. acuminata). Therefore,Musa breeders are interested in the determination of ploidy and its effects on phenotypic expression of quantitative traits. The aim of this research was to examine the reliability of stomatal and other phenotypic traits to determine ploidy in segregating plantainbanana hybrid families. Stomatal density and size were significantly correlated (P<0.01) with ploidy, although the correlation coefficients were not high (r=–0.49 and r=0.47, for stomatal density and size, respectively). High density of small stomata was correlated with low ploidy level, and vice versa. However, stomatal size and density were also influenced by a significant genotype effect (P<0.001) within the same ploidy level. Ploidy had an important effect on fruit traits and plant height in the hybrids of Obino l'Ewai×Calcutta 4, but this was not so clear in Bobby Tannap×Calcutta 4 hybrids. Obino l'Ewai derived tetraploids have medium to tall plants with large bunches and big fruits. Most of the tetraploids derived from Bobby Tannap have short stature due to the gene action of the dwarf,dw, allele. Also, a few selected diploids derived from Bobby Tannap outyielded their non-selected tetraploid full-sibs. In conclusion, chromosoem counting remains the only accurate proof of ploidy levels inMusa germplasm.     

Correlation between α-amylase gene expression and seedling vigor in rice

Summary This report examines the relationship between seedling vigor, -amylase enzyme activity and -amylase mRNA accumulation in ten varieties of rice (Oryza sativa L.) grown at two temperatures (15°C and 30°C). A significant, positive correlation was observed between seedling vigor, -amylase enzyme activity, and the accumulation of mRNA from one rice -amylase gene (RAmy1A) at both temperature regimens. The results of this study support previous experiments which have correlated -amylase enzyme activity to seedling vigor. We have extended this correlation to the expression of one of ten genes that comprise the rice -amylase multigene family. These results suggest that the expression of -amylase gene RAmy1A is an important, and possibly rate-limiting factor in determining seedling vigor in rice.