Comparative morphological and anatomical studies of the dispersal mechanisms characterizing the wheat complex (Triticum L. and Aegilops L.) have documented patterns of adaptive radiation which may have significance for evolutionary relationships. These patterns, which form an array of diverse types of diaspores among the diploid taxa, appear conceptually to have a starting point in the dimorphic inflorescence of Ae. speltoides. Separate dispersal trends, centered primarily in features of rachis disarticulation, lead in the direction of novel diaspore types for Aegilops and in the direction of domestication for Triticum. With respect to the taxonomy, this structural evidence supports the traditional Linnaean generic circumscriptions and suggests a need for a monographic revision of Triticum. In documenting the dispersal mechanisms, these studies have clarified conventional interpretations and have offered new insights on the developmental relationships linking the wild and domesticated taxa of the wheat complex. Although genetic studies were not encompassed within this research, a consideration of the genetic explanations for rachis disarticulation and glume closure suggests that the phenotypic traits typically used in genetic studies are not well understood. Given that the reticulate nature of genomic relationships in the wheats is coupled with intergrading variation and polymorphic species, a proposal is made for a broader evolutionary view than is found in the strict cladistic concept. This proposal emphasizes the need of an improved understanding of fundamental structural traits and an inclusion of these traits in evolutionary analyses. / Graduation date: 1995

This study was conducted to evaluate the kernel, flour and dough qualities and dietary fiber content of hulled wheats. Experimental design was separate randomized complete block designs for hulled wheat species with four field replicates. According to the results, significant differences (p<0.05) were observed in kernel quality, flour, and dough quality compared to common bread wheat. Einkorn and spelt reported significantly lower insoluble dietary fiber and total dietary fiber content, in contrast emmer had contents with both higher and lower genotypes. Interestingly, few genotypes of hulled wheat had a higher content of low molecular weight soluble dietary fibers (LMW-SDF) such as fructo and galacto oligosaccharides. Overall, hulled wheats differed from modern bread wheat in their kernel, flour, baking and nutritional quality. Moreover, due to higher LMW-SDF content, hulled wheats would be a potential candidate for breeding and producing health beneficial novel food products.

During the past few years there have been numerous studies made of various characters in wheat. Some characters which were thought at first to be simple in inheritance have since been found to be rather complex. The data in the following pages are the results of an investigation made to study the inheritance of awns in a cross between Hard Federation and Kota varieties of wheat. Until the last few years awn inheritance in wheat has been regarded as extremely simple, that is, as being dependent on a single factor difference. The awns of the F1 plants have nearly always been intermediate in length between the awns of the two parents with the F2 ratios 3:1 or 1:2:1, awnlessness usually being regarded as dominant. Recently, however, it has become apparent that the inheritance of awns is much more complex than the original data indicated. Several workers have found two independent factors and one has found two factors segregating in such a fashion as strongly to suggest linkage between these two factors.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet. / Härtill 6 uppsatser.

[Abstract]Quantitative Trait Loci (QTLs) for polyphenol oxidase and xanthophyll have a significant impact on variation in wheat flour for noodle colour and colour stability. QTLs from two Australian wheat cultivars, Sunco and Tasman, have been backcrossed into two Chinese wheat varieties, Chuanmai 22 and Mianyang 11, to assess marker predictability for these important traits in significantly different genetic backgrounds. The concept of Marker-Assisted-Selection (MAS) is being trialled in this study as a proposed method for wheat improvement. In this approach molecular markers are used in conjunction with backcross breeding methods to introgress specific characters into elite breeding materials, with the goal of improving the quality attributes of wheat for the Asian noodle market. After three single seed descent generations, the backcross populations generated allow four QTLs to be investigated. These include two for polyphenol oxidase (chromosome 2A and 2D) and two for xanthophyll (chromosome 3B and 7A). This research was successful in identifying microsatellite markers that are capable of predicting PPO activity levels and Xanthophyll content within the backcross populations. These microsatellites were validated as useful markers for these quality traits, as they have also found to be important in the Sunco x Tasman doubled haploid population. The combination of marker assisted selection and backcrossing has generated three lines that contain different combinations of the PPO activity and Xanthophyll content QTLs. These lines have been found to produce low levels of PPO activity and have a low Xanthophyll content. This improvement in flour colour and colour stability highlights the potential of marker assisted selection as a useful tool in wheat breeding.

Examensarbete.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.