Vitreousness is an important quality characteristic that affects the yield of semolina during milling of durum wheat. It has been observed that kernel vitreousness seems to be lower when durum is exposed to damp conditions just before harvest. The main objective of this research was to determine the effect of high relative humidity (RH) on kernel vitreousness of ten durum wheat cultivars. Spikes were exposed to 88% RH at room temperature for 1 and 3 days. This resulted in increased spike moisture, kernel moisture and kernel size. Vitreous kernel content (vitreousness) decreased 23.6% after spikes were exposed to high relative humidity for 3 days. Exposure to 88% RH caused the greatest decline in vitreousness with the cultivar ‘Ben’.
Authors:I. Arduini, L. Ercoli, M. Mariotti, and A. Masoni
Elhani, S., Martos, V., Rharrabti, Y., Royo, C., García del Moral, L.F. 2007. Contribution of main stem and tillers to durum wheat (
) grain yield and its components grown in Mediterranean environments. Field Crops
Authors:L. Ercoli, I. Arduini, M. Mariotti, and A. Masoni
Durum wheat (
Desf.) is commonly grown in Mediterranean conditions, where temperature stress during grain filling can limit productivity. This research was performed to evaluate the effect of temperature during grain filling on dry matter and nitrogen dynamics in two Italian durum wheat varieties, Appio and Creso, grown with different nitrogen availabilities. The experiment compared two different temperature regimens, one within the normal range occurring during grain filling in Central Italy, the other within the normal range occurring in the southern regions of Italy (20/15 °C and 28/23 °C day/night, respectively). Plants were grown in pots outdoor until anthesis and afterward were placed in growth chambers. Results showed that nitrogen fertilization and post-anthesis temperature affected growth, accumulation and partitioning of dry matter and N in durum wheat which, in turn, modified grain yield and N content. Grain yield was better expressed at 20/15 °C, while grain protein concentration was favoured under the 28/23 °C temperature regime. Higher temperature promoted remobilization of dry matter and restrained current photosynthesis, but reduced grain yield, indicating that the loss of photosynthesis could not compensate for the gain from increased remobilization. Grain N content, on the contrary, was promoted under the higher temperature regime, as high temperature reduced N remobilization but did not inhibit root water and nitrogen uptake, given that no water shortage occur.
Authors:L. Cabrera-Bosquet, G. Molero, A. Stellacci, J. Bort, S. Nogués, and J. Araus
The application of spectroradiometric index such as the normalized difference vegetation index (NDVI) to assess green biomass or nitrogen (N) content has focused on the plant canopy in precision agriculture or breeding programs. However, little is known about the usefulness of these techniques in isolated plants. The few reports available propose the use of a spectroradiometer in combination with special adaptors that improve signal acquisition from plants, but this makes measurements relatively slow and unsuitable. Here we studied the direct use (i.e. without adaptors) of a commercial cost-effective spectroradiometer, GreenSeeker™ (NTech Industries Ins., Ukiah, California, USA) provided with an active sensor (i.e. equipped with its own source of radiation) for measuring NDVI in four genotypes of durum wheat (Triticum turgidum L. var. durum) grown in pots under a range of water and N regimes. Strong correlations were observed between NDVI measurements and dry aboveground biomass (AB), total green area (TGA), green area without spikes (GA) and aboveground N content (AN). To prove the predictive ability of NDVI measured under potted conditions, linear regression models for each growth trait and for plant N content were built with the data of two genotypes. The models accurately predicted growth traits and N content, confirming the direct relationship between total plant biomass and spectroradiometric readings.
Authors:A. Rascio, E. Carlino, G. Nicastro, C. Platani, M. Russo, and N. Fonzo
A wheat (Triticum turgidum L. var. durum) mutant, designated k-plus, constitutively possesses high leaf potassium content and light-green leaves. To study the genetic basis of these traits and to find out their association, k-plus mutant was crossed to the wild type (WT) Trinakria, F1 and F2 populations were developed. The flag leaves of parental lines, F1 and F2 progeny were assayed for ion content, at the heading stage. Potassium content was greater in k-plus than in WT; the F1 hybrids behaved like to the WT, in both potassium and leaf colour. The number of genes conditioning leaf potassium content, was not more than one, as estimated by Castle-Wright method. A single recessive locus controls potassium content of k-plus mutant, with the wild type allele completely dominant over the new mutant. Broad sense heritability can be considered sufficient to obtain progress from selection, of k-plus phenotype. Light-green leaf colour was inherited as monogenic recessive allele, which co-segregate with the locus controlling potassium accumulation. Light-green F2 sub-population had, on the average, significantly more potassium content than green F2 sub-population. These preliminary results encourage further physiologic and genetic analysis of k-plus mutant.
Authors:S.M. Pirseyedi, A. Kumar, F. Ghavami, J.B. Hegstad, M. Mergoum, M. Mazaheri, S.F. Kianian, and E.M. Elias
Fusarium head blight (FHB) damage in durum wheat (Triticum turgidum L. var. durum Desf., turgidum) inflicted massive economic losses worldwide. Meanwhile, FHB resistant durum wheat germplasm is extremely limited. ‘Tunisian108’ is a newly identified tetraploid wheat with FHB resistance. However, genomic regions in ‘Tunisian108’ that significantly associated with FHB resistance are yet unclear. Therefore, a population of 171 backcross inbred lines (BC1F7) derived from a cross between ‘Tunisian108’ and a susceptible durum cultivar ‘Ben’ was characterized. Fusarium graminearum (R010, R1267, and R1322) was point inoculated (greenhouse) or spawn inoculated (field) in 2010 and 2011. Disease severity, Fusarium-damaged kernel (FDK) and mycotoxins were measured. Analysis of variance showed significant genotype and genotype by environment effect on all traits. Approximately 8% of the lines in field and 25% of the lines in greenhouse were more resistance than Tunisian108. A framework linkage map of 267 DArt plus 62 SSR markers was developed representing 239 unique loci and covering a total distance of 1887.6 cM. Composite interval mapping revealed nine QTL for FHB severity, four QTL for DON, and four QTL for FDK on seven chromosomes. Two novel QTL, Qfhb.ndsu-3BL and Qfhb.ndsu-2B, were identified for disease severity, explaining 11 and 6% of the phenotypic variation, respectively. Also, a QTL with large effect on severity and a QTL with negative effect on FDK on chromosome 5A were identified. Importantly, a novel region on chromosome 2B was identified with multiple FHB resistance. Validation on these QTL would facilitate the durum wheat resistance breeding.
Authors:X. Wu, H. Cárcamo, B. Beres, F. Clarke, R. DePauw, and B. Pang
Host plant resistance in the form of wheat with the stem lumen filled with pith has been the main strategy to manage the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae) - a major pest of wheat in the northern Great Plains of North America. Recently a new source of resistance has been made available combining a single dominant solid pith gene from durum wheat (Triticum turgidum L. var. durum) with spring bread wheat cultivars. Our study had two objectives: (i) assess levels of C. cinctus damage and larval C. cinctus mortality in wheat with the novel solid germplasm, conventional solid-stems and susceptible cultivars; and (ii) determine plant genotype effects on populations of C. cinctus parasitoid Bracon cephi (Gahan) (Hymenoptera: Braconidae). The study was conducted in plots near Lethbridge, Alberta, Canada from 2003–2005. The novel solid-stemmed hexaploid G9608B1-L12J11BF02, solid-stemmed AC Eatonia and hollow-stemmed durum AC Navigator reduced the infestation level and girdling damage by C. cinctus. Another synthetic hexaploid B9973B03&AC4AW, hollow-stemmed AC Cadillac, McKenzie and AC Barrie were more susceptible to C. cinctus damage. Larval parasitism by B. cephi increased along with C. cinctus infestation levels. Stem solidness itself, regardless of source, had no direct negative effect on B. cephi but due to lower infestation and survival of C. cinctus in solid stem genotypes, the overall population of parasitoids was reduced. When planting monocultures of effective solid stem wheat, strategies to conserve populations of parasitoids should be considered for long term sustainable management of C. cinctus.