Evaluation of Fibre Flax (Linum usitatissimum L.) Performance under Minimal and Zero Tillage in Eastern Canada

The feasibility of producing fibre flax in minimum tillage or zero tillage (ZT) systems was investigated. The results were variable between the sites, which differed in soil type and previous cropping history. Tillage regime had no impact on fibre flax phenological development including number of days to emergence, days to flowering and days to harvest at either site. However, tillage regime had a significant effect on mean stem diameter, dry matter content and plant height at all three sampling dates at the sandy loam site, and a significant effect on mid‐season plant height at the clay site. At the sandy loam site, ZT plots had the highest populations of plants with the finest stem diameters, the lowest branching ratios, but the shortest plants by the end of the season. Overall, plant densities were greater, stem diameters thinner, and biomass production higher in the heavier soil of the clay site. These results indicate that under the growing conditions present in 1998, fibre flax can successfully be grown in minimum or ZT systems on different soil types in Eastern Canada. Moreover, the growth of fibre flax in these systems does not compromise the proportion of tall plants having thin stems and minimal branching, a critical quality parameter for fibre flax production.     

Influence of Seeding Depth and Seedbed Preparation on Establishment, Growth and Yield of Fibre Flax (Linum usitatissimum L.) in Eastern Canada

Research was conducted at the Macdonald Campus of McGill University (Québec, Canada) at three sites in 1997 and one site in 1998 to determine the effects and interactions of seeding depth (0, 1, 2, 4 or 6 cm) and seedbed preparation (i.e. soil rolling): none, rolling before or rolling after seeding on fibre flax (cv. Ariane) establishment, growth and yield. Seedbed preparation had little impact on the parameters measured while seeding depth had a variable effect on plant density, plant height, stem diameter and retted straw yield. Seeding depths of 1–4 cm provided consistently good establishment, growth and yield results. In 1997, there was an interaction between seeding depth and seedbed preparation on plant height, branching ratio and retted straw yield, although results were generally variable and tended to be site‐specific. In 1998, there was an interaction between seeding depth and seedbed preparation on plant height and stem diameter prior to harvest, with the results varying for all seeding depth‐seedbed preparation treatment combinations except for the 2‐cm depth treatment. Rolling of the seedbed before seeding on lighter soils and at a depth of 2 cm on most soils can improve establishment, growth and yields of fibre flax under eastern Canadian growing conditions.     

Genetic improvement of spring barley cultivars grown in eastern Canada from 1910 to 1988

Summary Spring barley is an important feed crop in eastern Canada, and the development of high-yielding, high grain protein cultivars is desirable. This study was conducted to assess the impact of breeding on the yield and protein aspects of cultivar development, and to identify related changes in plant characteristics which may have been altered over time. A 3-year field experiment was conducted to evaluate twenty six-rowed spring barley genotypes representing the majority of cultivars developed from 1910 to 1988 for eastern Canada. The yields of barley cultivars released from 1935 to 1988 increased at a rate of about 0.03 t ha^-1 yr^-1, and showed no evidence of having reached a plateau. Increases in yield were associated with higher total dry matter production and harvest index, reduced plant height and increased lodging resistance. No consistent change in main stem or tiller yield components was observed. Grain protein concentration decreased progressively with time, especially with the newer cultivars. Reduction in grain protein concentration was not associated with lower protein content on a per grain basis, but rather with an increase in the amount of non-structural carbohydrate per grain. Total plant and grain N accumulation showed positive trends with time. No trends were observed for N harvest index, apparent post-heading N uptake, N retranslocation, and retranslocation efficiency. Thus, while the newer cultivars accumulated more total and grain N, proportional N partitioning to the grain was not altered.     

Nitrogen Fertilizer Rate and Timing Effect on Bread Wheat Protein in Eastern Canada

Nitrogen management for production of bread quality wheat ( Triticum aestivum L.) in eastern Canada has received little research attention. An experiment was conducted for 2 years at each of two sites in Québec to study the effect of level and timing of nitrogen (N) fertilizer application on grain protein concentration, protein content per seed, non-protein seed dry matter, grain protein yield and nitrogen harvest index (portion of plant N in the grain) of four hard red spring wheat cultivars known to have potential as bread wheats in eastern Canada. The soil types were Bearbroock clay (fine, mixed, non-acid, frigid, Humaquept) and Ste-Rosalie clay (typic, non-acid, frigid, Humaquept). The experiment was a 4 × 4 × 2 factorial. Four cultivars were used: Columbus, Katepwa, Max and Hege 155–85. In both years 0, 60, 120 and 180 kg Nha⁻¹ were applied either all at seeding or 60 % at seeding and 40 % at heading. Grain protein concentration and grain protein yield increased consistently with increasing N fertilizer and with split N application. Nitrogen harvest index was not increased by increasing applications of N fertilizer. Protein content per seed was more critical in determining grain protein concentration than non-protein seed dry matter content. The western Canadian cultivars Columbus and Katepwa generally had greater grain protein concentration than the European cultivars Max and Hege 155–85, With reasonable N fertility the grain protein concentration of spring wheats grown in eastern Canada are sufficient for bread production.     

2种穗型小麦品种若干性状差异的比较

为了探明胶东地区适宜的小麦品种类型与育种方向,通过11个不同的小麦基因型,采用t测验法对2种穗型小麦品种的若干性状差异进行了研究。结果表明:大穗型品种的单茎草重、茎质系数、穗粒数、千粒重、穗粒重比多穗型品种高0.958 g、0.011 g/cm、5.354粒、5.460 g、0.504 g,均达到极显著水平;多穗型品种的单位面积穗数、经济系数和群体产量比大穗型品种高289.847万/hm2、0.027、859 kg/hm2,均达到极显著水平。在胶东地区生态条件下,应以分蘖力中等、茎秆粗壮、成穗率高、产量三因素协调的多穗型品种为主攻方向。     

Evaluation of Five Most Commonly Grown Cotton Cultivars (Gossypium hirsutum L.) Under Mediterranean Conditions: Productivity and Fibre Quality

Studies were conducted in four regions of central Greece (Larisa, Karditsa, Livadia, Thiva), to evaluate the productivity and fibre properties (fibre strength and fibre length) of the five most commonly grown cotton cultivars in these regions. The experiments lasted for 6 years (1995–2000). All the characteristics tested were strongly influenced by the factors ‘year’, ‘cultivar’ and ‘region’. Significant cultivar × region, year × cultivar, region × year and cultivar × region × year interactions occurred for all the characteristics studied. The cultivar Alegria had the highest seed‐cotton and lint yield, while Aria had the lowest ones. Both cultivars gave the highest mean lint percentage but the lowest mean boll weight (MBW). Alegria had the lowest fibre strength, while Aria had the highest. The Acala‐type cultivars, Acala SJ2 and Zeta 2, had intermediate seed‐cotton and lint yield, while Vered 171 had high seed‐cotton and satisfactory lint yield. The three cultivars mentioned above had the highest MBW and very good fibre strength. Positive correlation was observed between fibre strength and length. In spite of the fact that mean fibre length was statistically the same in all cultivars, it was influenced by the factor ‘year’, as a result of different weather conditions. The year 1996 was the most unfavourable one for seed‐cotton yield and MBW, because it was characterized by lower than average air temperatures and rather dry conditions for all study sites. The factor ‘region’, a combination of different climatic conditions and cultural practices, influenced significantly all the parameters studied.     

Varietal Differences of Wheat and Triticale to Water Stress

Six wheat ( Triticurn aestivum L.) and ten triticale (x Triticosecale Wittmack) cultivars were screened for water stress tolerance during germination and seedling stages in the laboratory and growth chamber, respectively. Germinating seeds and hydroponically-grown seedlings were subjected to osmotic stresses of –0.3 and –0.6 MPa using polyethylene glycol M. W. 8000. Both species and cultivar differences were found among the tested genotypes for all the parameters analyzed in both germination and seedling tests. Germination stress index was lower for seed exposed to -0.6 MPa than for -0.3 MPa osmotic stress. A significant relationship was found among plant height, fresh weight and dry weight stress indices evaluated during the seedling test. The cultivars that grew taller under stress conditions had greater dry matter accumulation, as well as higher germination and water uptake stress indices indicating the reliability of height to predict cultivar performance under such conditions. The cultivars Stacy (wheat) and Eu 14/15 (triticale) had higher dry matter accumulation, higher water uptake and leaf water potential, greater height and better germination under stress conditions than the other cultivars tested. Conversely, the cultivars GA 781014 (wheat) and Am 4147 (triticale) performed poorly with respect to all the parameters analyzed. Based on results from germination and seedling tests, the cultivars Stacy and Eu 14/15 were selected for more stress studies in the greenhouse and field.     

红麻产量和纤维品质性状的遗传效应与杂种优势分析

红麻产量与品质性状的各项遗传效应、关联性及其杂种优势表现是杂种优势利用的基础,采用加性-显性遗传模型,分析了7个杂交红麻亲本和21个F1 代组合的12个产量与品质性状的研究结果表明,（1）株高、鲜皮厚、单株干皮重、千粒重、纤维支数同时受到加性和显性效应的控制;而茎粗、单株干茎重、皮骨比、出麻率、单株纤维重、精     

用灰色关联系数法对26个苜蓿品种生产性能的综合评价

为筛选最适宜在呼和浩特地区种植的苜蓿品种,应用灰色关联度分析研究了生长在呼和浩特地区的26个国内外优良苜蓿品种的生产性能。结果表明:众多性状中株高对鲜草产量的贡献最大,其次是单株重、单枝重、茎粗、分枝数、干鲜比,而茎长和根茎粗对苜蓿生产性能影响较小。评价筛选出牧野综合性状最好,生产性能优异,其次为射手2号、润布勒、金皇后、牧歌,可广泛在该地区推广应用。     

干旱胁迫对彩色棉花农艺、品质性状及水分利用效率的影响

为了探索干旱胁迫对彩色棉花主要性状的影响及其水分利用机理,选用7个不同色彩的棉花品种(系),在常规灌溉、胁迫灌溉和生育期不灌溉3种环境条件下,调查其农艺性状、品质性状、水分利用效率(WUE)及产量。结果表明,干旱胁迫下不同色彩棉花品种的单株成铃数、单铃重、株高、花铃期叶片数、有效果枝数、收获指数、果节数、籽指、茎粗和果茎节间长度减少,衣分增加;灌水量减少一半,参试棉花品种的产量均降低,不灌溉处理的籽棉产量与常规灌溉间差异显著(P<0.05);籽棉产量的降低幅度品种间存在较大差异(P<0.05),棕色棉的减产幅度高于绿色棉。常规灌溉处理下,白色棉花水分利用效率高于棕色棉花和绿色棉花,而后二者差异不显著;干旱胁迫下,棕色棉花的水分利用效率高于绿色棉花。与水分利用效率相关的主要农艺性状、品质指标是：叶片数、单株成铃数、有效果枝数、果节数、株高、收获指数、单铃重、主茎节间长度、茎粗、籽指、衣分。     

Genetic variation, heritability and progeny testing in meadow bromegrass

Meadow bromegrass is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. Because relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate genetic parameters and assess breeding methodologies for meadow bromegrass. Forty half‐sib (polycross and open‐pollinated) and full‐sib (selfed) progenies were evaluated for dry matter and seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fibre and acid detergent fibre. Genetic variation for seed yield, harvest index, and plant height was significant in the open‐pollinated and selfed tests. Genetic variation estimates for dry matter yield were negative (polycross), not significant (open‐pollinated), or significant (selfed). Estimates of genetic variation for quality traits were not significant, except for acid detergent fibre (selfed). Correlations among characters indicated that it is possible to simultaneously improve seed and forage yield. Rankings of progenies by the half‐sib tests for forage and seed yield were not altered by the use of the synthetic parental value (SV_i), which includes information from selfed progeny. The polycross progeny test did not discriminate parents as well as the open‐pollinated and selfed tests; this may have been a result of non‐random pollination in the polycross. Correlation among the progeny tests, showed that open‐pollinated and selfed progeny tests agreed for all characters, except for harvest index, while correlation between polycross and selfed tests were significant for six characters but not dry matter yield, and acid and neutral detergent fibres. The most dissimilar tests were polycross and open‐pollinated, with significant correlations found only for fertility index, height, spread and neutral detergent fibre. It was concluded that there was significant variation and moderate heritability for most traits in the meadow bromegrass populations evaluated, and that the open‐pollinated progeny test is the method of choice for selecting parents for synthetics of this species.     

Primary Growth Parameters of Three Alfalfa Cultivars Adapted to Highland Climatic Conditions

An irrigated field study was conducted to determine the relative importance and inter‐relationships of growth parameters of three dormant alfalfa (Medicago sativa L.) cultivars grown in the highlands of Eastern Anatolia, Turkey, in 2000–2003. The fast‐growing cultivar Savas had the greatest dry matter (DM) yield at the final sampling date with the greatest mean crop growth rate. In addition to a greater relative growth rate (RGR), this cultivar had more stem branching and greater leaf area in the canopy, which resulted in greater leaf area index (LAI) and greater leaf area duration. Despite the considerable increase in leaf area ratio (LAR: leaf area per unit shoot DM), the reduction in RGR of all cultivars over time was the result of a large decline in net assimilation rate (NAR) due to increasing specific leaf area (SLA). Intracultivar variation in the RGR of alfalfa is mainly determined by NAR and SLA, and both were significantly higher for Savas than the other two cultivars. The relative importance of NAR and SLA to RGR changed due to increasing self‐shading as the LAI of the canopy increased, creating a trade‐off between NAR and SLA.     

Susceptibility of European cultivars of Italian and perennial ryegrass to crown and stem rust

A set of 15 Italian (Lolium multiflorum), three hybrid (L. boucheanum) and 33 perennial ryegrass (L. perenne) cultivars were evaluated for their rust susceptibility in the field. The cultivars were grown in 2001, 2004 and 2007 at 29, 32 and 27 European sites, respectively. Rust incidence was scored during different growth cycles using a scale from one (no rust) to nine (susceptible). Crown rust (Puccinia coronata f. sp. lolii) was the most frequently observed rust species on Italian, hybrid and perennial ryegrass during all three experimental years. There was a highly significant difference in mean crown rust scores among Italian and perennial ryegrass cultivars, respectively, in each of the 3 years. The ranking of the cultivars was very consistent across the different sites within each year (with some exceptions), despite a significant interaction of cultivar response with sites. Moreover, the rank order correlations of mean cultivar rust scores were highly significant (r > 0.9) between the years. Stem rust (P. graminis f. sp. graminicola) occurred almost exclusively on perennial ryegrass. The cultivars showed significant variation in stem rust susceptibility. Rank order correlations of mean cultivar stem rust scores were mostly significant between sites within each year and highly significant between the years. The ranking of perennial ryegrass cultivars was different depending on whether crown or stem rust was scored. However, the rank order correlation between the mean disease scores of the cultivars for the two pathogens was low but still significant. At a particular site the assessment of crown or stem rust was in most cases very consistent over the period of experimentation. Therefore there was no evidence that rust resistance of an individual cultivar was overcome by the rust pathogen at a particular site over the 7 years of experimentation.     

Influence of Sowing and Harvest Time on Fibre Flax (Linum usitatissimum L.) in the Mediterranean Environment

Triennial field trials were carried out at Viterbo, central Italy, to investigate the influence of the sowing time, nitrogen fertilization and harvest dates of the two fibre flax (Linum usitatissimum L.) varieties Belinka and Ariane. Our results showed that warm and dry weather conditions, prevailing from late spring onwards, caused excessive shortening of the growing cycle of spring crops, with negative consequences for seed and fibre yield and quality. However, autumn sowings gave interesting results. Stem dry weight ranged between 5.6 and 6.7 t ha^?1 for autumn sowings and between 1.9 and 4.1 t ha^?1 for spring sowings. In autumn sowings, plant height and seed yields were also increased. Seed germinability was good even for early harvest dates. Stem dry weight remained constant at harvest dates following yellow‐green ripening, indicating that biomass was no longer allocated to the stems after that phase.     

品种和外植体对马铃薯脱毒试管苗生长的影响

采用二因素随机区组试验设计,通过测定苗鲜重、根鲜重、苗干重、根干重、叶片数、株高、茎粗、根长、根条数、节长、节数和叶面积等生长指标,研究了品种和外植体对马铃薯脱毒试管苗生物量,地上部和地下部的影响。研究结果表明:3个不同成熟期品种、3种不同外植体部位对马铃薯单株根鲜重、苗干重、根干重、株高、茎粗、节长和根冠比影响有显著性交互作用(p<0.05),说明不同品种和外植体对马铃薯脱毒试管苗生长发育有直接影响,其余性状受品种和外植体交互作用影响不显著;3个不同成熟期品种马铃薯的苗鲜重、根鲜重、苗干重、根干重、叶片数、茎粗、节长、节数、根冠比和根条数受品种影响显著(p<0.05),其余性状受品种影响不显著;3种不同外植体处理对马铃薯的根鲜重、苗干重、根干重、株高、茎粗、节数、叶面积和根冠比有显著性影响(p<0.05),其余性状受3种外植体的影响不显著。其中,以一个节段转接最有利于马铃薯脱毒试管苗的生长。     

Comparison of genetic diversity of flax (Linum usitatissimum L.) between Canadian cultivars and a world collection

This study reports results of phenotypic measurements of genetic diversity in the world collection of flax maintained by Plant Gene Resources of Canada (PGRC) and compares the range of diversity in the world collection with the diversity observed in 19 Canadian registered flax cultivars. Morphological and seed‐oil characters were used to describe the phenotypic diversity in 2331 flax accessions. The plants were grown by PGRC at Saskatoon, Saskatchewan, Canada, in 1998 and 1999. The comparison between the Canadian cultivars and the world collection was based on single characters, as well as on character complexes by application of an existing intraspecific classification for the species. Considering single quantitative or qualitative character expressions, the Canadian cultivars represented a wide range in diversity for the species. The variation of characters Canadian plant breeders have selected for (e.g. plant height, seed weight, seed colour, petal colour, oil content) was reduced further than those characters not focused on by plant breeders (e.g. dotting of the sepals, style colour, ciliation of capsule septa, oil quality characters). A comparison of diversity based on the intraspecific classification proposed for flax by Kulpa and Danert, who described 28 botanical varieties, showed that all Canadian cultivars belong to two botanical varieties. This study demonstrates the usefulness of agrobotanical characterization of genebank collections for plant breeding and illustrates the application of the traditional method of intraspecific classification for comparison of gene pools.     

Linseed (Linum usitatissimum L.) Cultivars and Breeding Lines as Stem Biomass Producers

Linseed ( Linum usitatissimum L.) stems, which contain bast fibres, make up a considerable part of the linseed biomass, but are considered a by-product of no value. The feasibility of cultivating existing linseed cultivars and breeding lines for dual-purpose use of stem and seed was studied in 1995–97 in Jokioinen, Finland. Finnish linseed cv. Helmi was compared with 10 linseed genotypes and one flax cultivar for stem yield, ratio of stem yield to seed yield, and plant stand height and density. The stem yield of cv. Helmi averaged 1317 kg dry matter ha^-1. Significantly higher stem yields were produced by breeding lines Bor 15 and Bor 18 and cvs Gold Merchant, Norlin and Martta. The cv. Helmi produced lower stem yield than seed yield while breeding lines Bor 15 and Bor 18 and cvs Gold Merchant and Martta yielded more stem than seeds. The difference in the ratio of stem yield to seed yield between them and cv. Helmi was statistically significant. The mean plant stand height was 60.3 cm and the final plant density 594 plants m^-2. No relationship was found between stem yield and height or density. Within 2 days of seed threshing, stems of early maturing Finnish genotypes dried up in the field to nearly 15 % moisture content, even in the middle of September (1996). The early maturing breeding lines Bor 15 and Bor 18, with their significantly higher stem yields relative to cv. Helmi, are recommended for dual-purpose use.     

The relationship of stem and seed yields to flowering phenology and sex expression in monoecious hemp (Cannabis sativa L.)

Flowering phenology and sexual dimorphism are two major features that affect stem and seed production in hemp (Cannabis sativa L.), a short-day naturally dioecious plant. The sowing time is of primary importance because it affects flowering time and thereby influences stem yield. In spite of their unstable sexual phenotype, monoecious cultivars facilitate the harvest of both stems and seeds by reducing crop heterogeneity. The main objective of this paper was to determine the stem and seed yields for five monoecious hemp cultivars in relation to their flowering phenology and sex expression. Sowing was carried out on five distinct dates during 2007 and 2008 at two sites in Belgium. The duration from sowing to flowering in days, both stem and seed yields and the seed harvest index decreased when sowing was postponed from mid-April to the end of June. The stem and seed yields from the mid-April sowing (approximately 12.5 and 1.9 t ha⁻¹, respectively) were within the ranges that were reported for fibre and both fibre and seeds production, respectively, in monoecious hemp. No interaction was observed between the sowing date and cultivar for both yields. Sex expression varied among cultivars, indicating that it might be selected, and was partly linked to earliness. Stem yields were lowest in the earliest cultivar (Uso 31) and highest in the latest one (Epsilon 68) while seed yields were lowest in the most masculinized and earliest cultivar (Uso 31) and highest in the most feminized and early (Fedora 17) or mid-early (Felina 32) ones. Both stem and seed yields correlated best with the duration from sowing to full female flowering or from sowing to the end of male flowering.According to our results, harvesting the seeds in addition to the stems in monoecious hemp requires early sowing and the selection of feminized early or mid-early cultivars, earliness depending on the climatic conditions in the cultivation area. Therefore, it might be agriculturally valuable to take sex expression into account in addition to earliness during the selection of cultivars that are adapted to a dual purpose.     

菊芋株型在高产育种中的作用

本试验通过在苏北滨海盐土上的试验研究菊芋株型在菊芋选育中的作用。结果如下：1）在2007年和2008年,南芋1号鲜产量和干产量比对照青芋2号和野生种高,2007年与2008年试验结果没有显著差异,而2007年与2008年品种间鲜产量及干产量差异显著; 2）南芋1号以植株生长势强,主茎粗,分枝多,茎干高,在盐土上植株生长势强,青芋2号有效分枝基本没有,茎秆细,开花多,在盐土上植株生长势弱,而野生品种茎秆较南芋1号细,分枝少,在盐土上植株生长势一般,茎干高度低于南芋1号;3）2007年和2008年块茎产量显著高于分枝数少的品种块茎产量,而各品种在2007年和2008年间互相差异不显著;4）分枝数与地上部生物产量、分枝数与块茎鲜重产量及分枝数与块茎干重产量的相关性分析显示其R2均达极显著水平。菊芋育种应注重选育分枝多的株型。     

木薯单株产量与主要农艺性状的相关性研究

探讨木薯单株产量与主要农艺性状的相关性,以提高木薯育种效率,为木薯品种选育奠定基础。采用13 份木薯种质资源为试验材料,通过相关与通径分析等方法,探讨了11 个主要农艺性状与单株产量之间的相关性以及不同种质资源单株产量之间的差异性。结果表明：NK-2、NK-6、NK-7、NK-10、NK-11、‘新选048’与‘华南205’之间的单株产量呈显著差异;单株产量与块根数呈极显著正相关,与收获指数、生物产量、最长薯长、主茎高度呈显著正相关,与干物质含量呈显著负相关;通径分析结果表明,各农艺性状对单株产量的直接通径系数和决定系数的大小顺序一致,依次为：块根数、最长薯长、生物产量、主茎高度、叶保留高度、干物质含量、收获指数、地上部鲜重、淀粉含量、主茎粗、株高。由此表明,选育高产木薯需要关注的主要农艺性状有：块根数、最长薯长、生物产量、主茎高度、叶保留高度、干物质含量、收获指数等。