Genetic divergence is not the same as phenotypic divergence

Far too often, phenotypic divergence has been misinterpreted as genetic divergence, and based on phenotypic divergence, genetic divergence has been indicated. We have attempted to disprove this statement and call for the differentiation of phenotypic and genotypic variation

Multidimensional Analysis of Diversity in Genotypes of Winter Oilseed Rape (Brassica napus L.)

The effect of genotype, environment (year, location) and their interaction on seed yield and important breeding traits of 25 genotypes of winter oilseed rape were investigated under field conditions in Greater Poland. Multi-environmental field experiments were conducted in a randomized block design with four replications during three growing seasons in two locations. Five traits, such as the beginning of flowering, seed yield and its structure, the length of siliques, the number of seeds per silique and the weight of 1000 seeds were recorded. The tested Brassica genotypes showed significant differences in terms of yield and other investigated traits across harvesting years and growing locations. Analysis of variance indicated that the main effects of genotypes, locations and years as well as all interactions were significant for all traits of study. The correlation coefficient between the investigated traits displayed strong negative relationships between seed yield and the beginning of flowering (except E2). The use of multivariate statistical methods in this study allowed for the simultaneous characterization of 25 tested genotypes in terms of several traits. Visualization of the experimental results and finally the distribution of Brassica genotypes in space of two first canonical variates showed a variation between the cultivars, double low, resynthesized and lines with changed fatty acid content in terms of yield and its components, as well as the beginning of flowering

Variability of the agronomic characters in different types of cultivars of winter oilseed rape (Brassica napus L.)

Winter oilseed rape cultivars (open-pollinated variety, four composite hybrids, one restored hybrid and the CMS ogu- ra line) were tested during two crop seasons of 2002/2003 and 2003/2004 in field trials at two locations in western Poland. The objectives of the present study were: to determine the variability of yield and the most important phenotypic traits of different types of winter oilseed rape cultivars and to analyse the genotypic variabi- lity of this cultivars by environment interactions. The growing se- asons differed especially in terms of water supply. Seed yield, yield components and some quality traits (oil content and total glucosi- nolate content) were recorded. The tested cultivars showed sub- stantial differences in terms of yield and other investigated traits. Analysis of variance indicated that the main effects of cultivar and locations were significant for all the traits of the study. Very high heritability estimates were obtained for seed yield (0.90–0.98), yield components (length of silique, number of seeds per silique and weight of 1000 seeds), and also for oil and glucosinolate con- tents. The correlation coefficients between the investigated traits displayed strong positive relationships between seed yield and the number of seeds per silique, chlorophyll content, and the length of flowering period. The results confirmed the higher productivity of hybrid cultivars, as well as their better adaptability to variable environmental conditions, especially drought

Cleaved Amplified Polymorphic Sequences (CAPS) Markers for Characterization of the <i>LuFAD3A</i> Gene from Various Flax (<i>Linum usitatissimum</i> L.) Cultivars

Depending on the variety, flax (Linum usitatissimum L.) provides an oil rich in omega-3 acids (especially 50% α-linolenic acid) with proven health properties, and is used as a raw industrial material. Alpha-linolenic acid is a polyunsaturated fatty acid easily subject to oxidative transformation. The auto-oxidation of α-linolenic acid is the main process contributing to off-flavor, color loss, and change in the nutritional value of flax oil. We used six flax genotypes differing in fatty acid content in our research. For all the DNA samples extracted from the leaf tissue of the studied flax, the new, cleaved amplified polymorphic sequences (CAPS) markers specific to the LuFAD3A desaturase gene were applied. A specific PCR product from the LuFAD3A flax gene comprising fragments of exon 5, exon 6, and the intron between these exons was digested using six various restriction enzymes. These experiments could differentiate between some of the studied varieties of flax. We also proved that the LuFAD3A gene mutation previously detected by other authors in the low-linolenic forms of flax (solin line 593–708) was absent in the low-linolenic forms of flax that we studied (Linola KLA and Linola KLB)

Estimation of seed yield in oilseed rape to identify the potential of semi-resynthesized parents for the development of new hybrid cultivars.

Resynthesized (RS) Brassica napus can be used to increase the genetic diversity of this important crop plant and to develop the heterotic gene pool required for successful hybrid breeding programmes. The level of heterosis in F1 hybrids depends on the individual performance of the parents and on the degree of genetic difference between them. However, RS forms obtained from crosses of B. rapa ssp. with B. oleracea ssp. possess many undesirable agronomic traits, such as low quality of seeds, low yield and seed oil content, high erucic acid level in the oil and high glucosinolate content in seed meal. Therefore, RS oilseed rape needs to be improved by crossing with natural double-low oilseed rape, leading to selected double-low quality semi-RS lines that can be used for breeding. In this study, we evaluated the seed yield potential of F1 hybrids derived from crosses between Ogura cytoplasmic male-sterility (CMS) lines and doubled haploid (DH) semi-RS lines with restorer gene in three locations in Poland. The genotype by environment interaction (GE interaction) and general combining ability (GCA) of the restorer and CMS line effects, as well as the effects of heterosis, were also assessed. The results of the study provide the first insights into the use of semi-RS lines as components for the development of new hybrid cultivars. Even the introduction of 50% of the RS oilseed rape genotype to natural restorer lines resulted in a marked heterosis effect, with seed yield ranging from 4.56% to 90.17% more than that of the better parent. The yield of the best hybrid amounted to 108.6% of the seed yield of the open-pollinated cultivar Monolit and 94.4% of that of the hybrid cultivar Arsenal. The best DH semi-RS line S1, which had a significantly positive GCA for seed yield, can be recommended as a possible parent for inclusion in breeding programmes aimed at developing new hybrid cultivars

Effect of Genotype × Environment Interaction for Seed Traits in Winter Oilseed Rape (Brassica napus L.)

Brassica napus (L.), winter oilseed rape (WOSR) or canola, is one of the most important oilseed crop species of the moderate climate zone. Improving the seed quality and yield makes the main target in breeding programs worldwide. In this study, we examined the genotype-by-environment (G&times;E) interaction with respect to six seed traits among 25 WOSR genotypes. The plant material included the registered canola cultivars, our newly developed mutant breeding lines and the Ogura F1 hybrids and their parental components, in addition to our domestic breeding lines including two semi-resynthesized (semi-RS) lines. The 25 genotypes were examined in field trials at two locations, in three growing seasons. Seed oil and protein content, total glucosinolates (GLS) content in seed meal and C18 unsaturated fatty acid (oleic, linoleic and linolenic) composition in seed oil were examined. The additive main effects and multiplicative interaction (AMMI) analyses revealed significant effects of both, genotype (G) and environment (E) as well as the G&times;E interaction regarding the analyzed seed traits. In our study, two Ogura F1 hybrids, a CMS line and a new high oleic mutant breeding line revealed high stability and good average values for most of the analyzed seed traits, thus making a valuable source of starting materials for further improvement