Modern Cultivars Research Articles

Dry matter and nutrient partitioning changes for the past 30 years of cotton production

AbstractModern cotton (Gossypium hirsutum L.) cultivars are more productive and have unique growth and fruiting characteristics due to optimization of genetics and management practices in the past 30 yr. The most recent work evaluating nutrient uptake and partitioning by cotton was conducted in the early 1990s, necessitating a re‐evaluation of nutrient accumulation and requirements in modern high productivity cultivars. Modern cultivar (FiberMax [FM] 958 and Deltapine [DP] 1646) resource allocation, including dry matter production, yields, and accumulation and partitioning of N, P, K, Ca, Mg, and S to different organs, was compared with that of a 1990s cultivar (Paymaster [PM] HS26) in 2018 and 2019. The modern cultivars tested in this study partitioned a greater percentage of dry matter, N, P, K, and S into the fruit than the older cultivar, highlighting the importance of partitioning for increased production potential of these cultivars from the 1990s to the 2010s. Greater efficiencies in partitioning and remobilization of N, P, K, and S resulted in 66, 88, 64, and 30% increase in the amount of lint yield produced for every unit of uptake, respectively, under favorable growing conditions. These findings suggest that existing fertility paradigm in cotton may underestimate the accumulation expectations during the middle and latter part of the growing season. These results can be a basis for optimizing nutrient application to address partitioning changes. Adjusting nutrient recommendations to the shift in cultivar growth characteristics may improve both yield and application efficiency of fertilizers.

Improving roller milling technology using the break, sizing, and reduction systems for flour differentiation

A key issue in breadmaking is to select the optimal milling strategy, as this has a significant impact on the quality of flour. Therefore, this work assesses if flour recovered from: (i) the break system, and (ii) the sizing and reduction system of the roller mill differ from control flour. Differences in flour yield, flour composition, dough rheology, and bread characteristics for an ancient cultivar (Conte Marzotto) and a modern cultivar (Nogal) were evaluated. For break system flour, lower fibre and higher starch content were found. Sizing and reduction system flours had higher fibre and phenolic content, and lower starch. Moreover, dough stability was higher for break system flour and, in the case of Nogal, a significant increase in bread specific volume was found. These results highlighted that the proposed strategy can be effective in producing diverse flours for different markets (e.g. consumers and bakers). In particular, break system flours have better rheological performance and improved bread characteristics, while sizing and reduction system flours have a more interesting nutritional profile. Further advantages of the method include its ease of application, no additional expenditure, no lengthening of milling time, increased profits, better product differentiation, and the expansion of the potential clientele.

Energy cane vs sugarcane: Watching the race in plant development

Sugarcane (Saccharum spp.) grows in all tropical and subtropical regions of the world, being cultivated in more than 100 countries. Modern cultivars are the results of interspecific crosses, having S. officinarum as the main genetic source, which results in high sucrose production. Energy cane is still a less rigorous definition, applied to cane cultivars that have higher biomass, although lower sucrose concentration. Despite the practical advance, little is known about the molecular and physiological basis of the energy cane productivity and robustness, a knowledge that can be very helpful for the development of cane varieties in general. In this work, we have explored the sprouting process, which is very irregular in sugarcane plantation and thereby a main cost factor. Our results could be summarized in three main contributions: first, we observed that energy cane has a physiological strategy very different from that one observed for sugarcane, starting with the shoot development and only thereafter beginning the root growth. After 10 days, the energy cane had a shoot height of 14.19 cm against of 4.24 cm of sugarcane. Nevertheless, we noticed the energy cane root presents a fast and vigorous development, overcoming the sugarcane root volume after 50 days, with 24.36 and 14.79 cm3, respectively. Second, we observed that the energy cane has homogeneity in the sprouting rate of the different internodes, regardless of their age. Finally, our data allowed us to propose that the greater growth seen in energy cane might be attributed to a vigorous rate of nocturnal growth with angulation in relation to the time of 11.89°, which is lower in sugarcane, with angulation of 5.47°.

Composition of Primary and Secondary Metabolite Compounds in Seeds and Pods of Asparagus Bean (Vigna unguiculata (L.) Walp.) from China.

Asparagus bean immature pods and seeds are popular as food products for healthy and functional nutrition. Gas chromatography with mass spectrometry was used to compare metabolomic profiles of seeds and pods yielded by old Chinese landraces and the modern cultivars ‘Yunanskaya’ and ‘Sibirskiy razmer’. About 120 compounds were identified. The content of a majority among groups of compounds was higher in pods than in seeds. The amount of free amino acids in pods was 47 times higher, polyols and phytosterols 5 times higher, phenolics 4 times higher, and organic acids and saponins 3 times higher than in seeds. Differences were found in the relative content of compounds. Among phenolic compounds, the dominant one for seeds was protocatechuic acid, and for pods 4-hydroxycinnamic acid. Only polyols were identified in seeds, but pods additionally contained ethanolamine, phytol, and phytosphingosine. The ratio for nonsaturated/saturated fatty acids was 2.2 in seeds and 1.4 in pods. Seeds contained more stigmasterol, and pods more β-sitosterol. Aglycones of saponins were identified: cycloartenol in seeds, α- and β-amyrins in pods. Oligosaccharides dominated in both seeds and pods. Landraces manifested higher protein content in pods, while modern cultivars had pods with higher contents of organic acids, polyols, monosaccharides, and fatty acids. The results obtained confirm the high nutritional value of asparagus bean seeds and pods, and the prospects of their use in various diets.

Impact of osmotic stress on the growth and root architecture of introgression lines derived from a wild ancestor of rice and a modern cultivar.

Many modern rice varieties have been intensively selected for high-yielding performance under irrigated conditions, reducing their genetic diversity and potentially increasing their susceptibility to abiotic stresses such as drought. In this study, we tested benefits for stress tolerance of introducing DNA segments from wild ancestor Oryza rufipogon to the modern cultivar O. sativa cv Curinga (CUR) by applying a gradient of osmotic stress to both parents and seven introgressed lines. Shoot growth of O. rufipogon had a high tolerance to osmotic stress, and the number of total root tips increased under mild osmotic stress. One introgression line showed greater shoot growth, root growth, and higher number of total root tips than the parent line CUR under osmotic stress. Abscisic acid (ABA) is a key hormone mediating plant responses to abiotic stresses. Both root and shoot growth of O. rufipogon were much more sensitive to ABA than CUR. Introgression lines varied in the extent to which the sensitivity of their growth responses to ABA and some lines correlated with their sensitivity to osmotic stress. Our results suggest that rice responses to ABA and osmotic stress are genotype dependent, and growth responses of rice to ABA are not a consistent indicator of resilience to abiotic stress in introgression lines.

Genetic Progress of Seed Yield and Nitrogen Use Efficiency of Brazilian carioca Common Bean Cultivars Using Bayesian Approaches.

Common bean (Phaseolus vulgaris L.) is one of the most important crops worldwide and is considered an essential source of proteins, fibers, and minerals in the daily diet of several countries. Nitrogen (N) is considered the most important nutrient for common bean crop. On the other hand, the reduction of chemical fertilizers is a global challenge, and the development of cultivars with more N use efficiency (NUsE) is considered one of the main strategies to reduce the amount of N fertilizers. Genetic progress of NUsE has been reported in several crops; however, there was still no quantity in common bean. In this study, our goal was to analyze the genetic progress of seed yield (SY) and NUsE-related traits of 40 carioca common bean cultivars release from 1970 to 2017 in eight environments under low (zero) or high N (40 kg ha−1) in top-dressing. Genetic progress, principal component analysis, correlations among traits, and cultivar stability were analyzed using Bayesian approaches. The lowest values of the deviance information criterion (DIC) for the full model tested indicated the presence of the genotype × N × environment interaction for all evaluated traits. Nitrogen utilization efficiency (NUtE) and nitrogen uptake efficiency (NUpE) were the traits that most contributed to discriminate cultivars. The genetic progress of SY under high N (0.53% year−1, 95% HPD = 0.39; 0.65% year−1) was similar to that obtained in low N conditions (0.48% year−1, 95% HPD = 0.31; 0.64% year−1). These results indicate that modern cultivars do not demand more N fertilizers to be more productive. In addition, we observed a high genetic variability for NUsE-related traits, but there was no genetic progress for these variables. SY showed negative correlation with seed protein content (Prot) in both N conditions, and there was no reduction in Prot in modern cultivars. Both modern and old cultivars showed adaptability and stability under contrasting N conditions. Our study contributed to improve our knowledge about the genetic progress of common bean breeding program in Brazil in the last 47 years, and our data will help researchers to face the challenge of increase NUsE and Prot in the next few years.

Priority trends and prospects of blackberry breeding in conditions of Central Russia.

This overview substantiates the possibility and expediency of blackberry breeding in Central Russia, where it is in demand, but not widespread in horticulture. Significant achievements of world breeding, which gave modern cultivars a large set of economically important qualities and growing interest in it all over the world, including Russian gardeners, make it relevant to work with blackberries as an object of selection, and as a promising garden plant. However, insufficient frost and winter hardiness of the bulk of the cultivars of this culture cause certain difficulties when growing it in the areas with cold winters to which the Central zone of Russia belongs. The expansion of the market of berry products also imposes increasingly high requirements on the complex of economic indicators of new cultivars, primarily the quality of blackberry fruit. In this regard, improving the existing range of varieties of the culture, increasing its adaptive properties and commodity qualities of berries are urgent tasks for breeders when creating new cultivars. The relevance of blackberry breeding is also dictated by the fact that in Russia its domestic range of varieties is represented by only one modern cultivar obtained in the southern region and adapted, first of all, to it. For the Central zone of the country, the cultivars of this plant have not been developed (except for the limited experiments of I.V. Michurin conducted almost 100 years ago). Therefore, the breeding of adapted cultivars of the culture in the climatic conditions of this region may be promising. It is also possible to grow here (with shelter for the winter) the cultivars already created abroad that can give with the right agricultural technology a good industrial harvest, which is confirmed by the practice of amateur and farm gardening, as well as scientific research. The purpose of this work is to designate the leading directions of blackberry breeding, the most important in the conditions of Central Russia and to show prospects of the development of new cultivars of this valuable culture in the specified climatic zone. The analysis of world trends and experience in the blackberry breeding and variety study, as well as the results of our own research of the culture conducted in the Orel region, allow us to consider it promising and relevant to work on improving the range of varieties of this plant in Central Russia. All priority areas of blackberry breeding, indicated in foreign and domestic breeding programs (winter hardiness, high quality of fresh and processed fruit, the correct shape of berries, their large size, the necessary values of biochemical composition, high productivity of plants, thornless shoots and high resistance to diseases and pests), are relevant for this region of our country, while high winter hardiness is currently the most important of them.

Morphoagronomic characterization and genetic diversity of a Brazilian okra [Abelmoschus esculentus (L.) Moench] panel

Okra [Abelmoschus esculentus (L.) Moench] has been neglected by breeders as few cultivars have been released over the last years, which contributes to yield stagnation. Developing modern cultivars is key to increase okra production. To provide information to efficiently improve okra cultivars, this study aimed to characterize and assess the genetic diversity of a Brazilian collection by using the Ward-MLM (Modified Location Model) multivariate procedure. Both quantitative and qualitative variables can be simultaneously considered in this strategy. Forty-six okra accessions from the active germplasm bank of Embrapa Hortalicas and the open-pollinated ‘Santa Cruz 47’ were characterized according to descriptors lists. Seven groups were identified comprising seven, six, fourteen, six, five, seven, and two genotypes, respectively. Group VII was the most distant in relation to the other groups, probably because of the greatest vegetative development and lowest fruit production. Variability was observed for most morphological traits. The grouping information will be useful for germplasm conservation management and for crossing strategies. Leaf length, leaf width, petiole length, stem diameter at plant base, and first flowering height contributed the most to genetic variation. The genetic variability verified in this study suggests a high potential for breeding new okra cultivars.

Fingerprinting of wheat protein profiles for improved distinction between wheat cultivars and species

AbstractBackground and objectivesWheat protein composition is commonly characterized by reversed‐phase (RP)‐HPLC‐UV after extraction of albumins/globulins, gliadins (ω5‐, ω1,2‐, α‐, and γ‐gliadins), and glutenins (high‐ and low‐molecular‐weight glutenin subunits). However, this traditional classification does not consider the individual distribution of peaks, resulting in loss of information on protein fingerprints. We developed a new approach to peak integration and evaluated its suitability to differentiate between wheat cultivars and species.FindingsIntegration events were performed every 20 s, and the relative proportions of the peaks were calculated. We compared the traditional and new integration methods on two sample sets, the first comprising 60 common wheat cultivars from 1891 to 2010 and the second comprising 40 common wheat, spelt, durum wheat, emmer, and einkorn cultivars. The new integration method performed better in differentiating old and modern common wheat cultivars and was also applicable to different wheat species.ConclusionsUnique cultivars were identified that stood out because of their protein composition. Four samples warrant further research to identify the specific proteins that are responsible for the differences.Significance and noveltyThe new integration allowed us to map the cultivar‐ and species‐specific fingerprints, identify cultivars with exceptional protein composition, and group similar cultivars.

Agronomic performance of durum wheat landraces and modern cultivars and its association with genotypic variation in vernalization response (Vrn-1) and photoperiod sensitivity (Ppd-1) genes

This study analyzed the relationship between important agronomic traits and major genes regulating flowering time in a panel of 151 Mediterranean durum wheat landraces and 20 modern cultivars. Field experiments were conducted under rainfed conditions during six crop seasons in northeastern Spain. Multivariate analysis of agronomic traits and genotypic data allowed the modern cultivars to be differentiated from the landraces and germplasm pools to be identified within the landraces associated with their geographic origin. The high frequency of the Vrn-A1c allele and the photoperiod insensitive alleles GS105 and GS100 at Ppd-A1 reduced time to anthesis and enlarged the grain filling period of the modern cultivars compared with the landraces. Ancient durums collected close to the domestication area of wheat showed a high frequency of the winter allele vrn-B1 and the photoperiod sensitivity allele Ppd-B1b. None of the allele variants or allelic combinations accounted significantly for variations in any agronomic trait of modern cultivars. Vernalization and photoperiod genes acted additively in explaining the genotypic variance for the agronomic traits of the landraces. Vrn-A1 alleles and Vrn-A1+Vrn-B1 allelic combinations significantly affected the number of grains per spike (NGS), thousand kernel weight (TKW) and grain filling rate (R), accounting for 9%?12% of the genotypic variance for these traits. Ppd-1 accounted for 6%?21% of the genotypic variance for R, grain filling duration (GFD), plant height (PH), biomass at anthesis (CDW) and harvest index (HI). Vrn-1+Ppd-1 allelic combinations accounted for 21%?26% of the genotypic variance for these traits. Except for NGS, the effect of vernalization and photoperiod genes on the agronomic traits was linked to their effect on anthesis time. The three-day delay in anthesis time caused by the allele Vrn-A1d irrespective of the allele Vrn-A1c resulted in increases of 10 % in R and 7% in TKW. The eight-day delay in anthesis time caused by the allele Ppd-A1(DelCD) compared with Ppd-A1(GS105) increased R by 19 % and PH by 28 %, but reduced GFD and HI by 10 %. None of the allele variants or allelic combinations at the Vrn-1 or Ppd-1 genes accounted significantly for variations in yield or number of spikes m?2 (NSm2).

Genetic Status of the Swedish Central collection of heirloom apple cultivars

Cultivated apple is one of the most widely grown fruit crops worldwide. With the introduction of modern apple cultivars, from foreign and national breeding programs, the use of local cultivars decreased during the 20th century. In order to minimize genetic erosion and avoid loss of special genotypes, a number of local clonal archives were established across Sweden, with the goal of retaining old and local cultivars. About 220 apple cultivars, appointed for preservation, obtained the status of mandate cultivars. Initially, they were identified based on pomological traits, but prior to the establishment of the Swedish Central Collection they were genotyped with simple sequence repeat (SSR) markers. SSR markers helped to evaluate the status of the preserved material, as well as to find the best possible true-to-type source for propagation, thus guiding the establishment of the Central Collection. Recently, 215 accessions from this collection were genotyped using the 20 K apple Infinium® single nucleotide polymorphism (SNP) array, in order to gain insight into its genetic structure. The initial SSR analysis confirmed the identity of multiple samples with the same cultivar name grown in different locations and identified several mislabeled samples. In the subsequent SNP analysis we identified 30 clonal relationships and a number of parent-offspring relationships, including 18 trios. We also identified five cultivar samples with inconsistent ploidy levels between the SNP and SSR data, in some cases indicating problematic samples preserved in either the Central Collection or some of the local clonal archives. These cultivars need further investigation to ensure their true-to-typeness. Furthermore, the Swedish Central Collection has continued to grow since the onset of this work and now contains additional cultivars, which should be included in future studies. The results indicate that a number of the preserved mandate cultivars holds high potential value for modern breeding programs.

Sugarcane genome architecture decrypted with chromosome-specific oligo probes.

Sugarcane (Saccharum spp.) is probably the crop with the most complex genome. Modern cultivars (2n=100-120) are highly polyploids and aneuploids derived from interspecific hybridization between Saccharum officinarum (2n=80) and Saccharum spontaneum (2n=40-128). Chromosome-specific oligonucleotide probes were used in combination with genomic in situ hybridization to analyze the genome architecture of modern cultivars and representatives of their parental species. The results validated a basic chromosome number of x=10 for S. officinarum. In S. spontaneum, rearrangements occurred from a basic chromosome of x=10, probably in the Northern part of India, in two steps leading to x=9 and then x=8. Each step involved three chromosomes that were rearranged into two. Further polyploidization led to the wide geographical extension of clones with x=8. We showed that the S. spontaneum contribution to modern cultivars originated from cytotypes with x=8 and varied in proportion between cultivars (13-20%). Modern cultivars had mainly 12 copies for each of the first four basic chromosomes, and a more variable number for those basic chromosomes whose structure differs between the two parental species. One-four of these copies corresponded to entire S. spontaneum chromosomes or interspecific recombinant chromosomes. In addition, a few inter-chromosome translocations were revealed. The new information and cytogenetic tools described in this study substantially improve our understanding of the extreme level of complexity of modern sugarcane cultivar genomes.

Biomass and Bioenergy Potential of Novel Interspecific and Intergeneric Hybrids of Saccharum Under Subtropical Climate

Sugarcane-derived biomass is an emerging source of renewable energy, which offers a promising opportunity to meet growing demands of biofuel. The modern cultivars do not fulfill required biomass and bioenergy potential due to their narrow genetic base and succumb to many stresses. We evaluated 24 hybrids derived from diverse genetic background of Saccharum spp. and allied genera with commercial checks. Intergeneric hybrids, viz ., KGS 99-100 (43.37 t ha −1 ) and GU 04-432 (35.24 t ha −1 ) involving Erianthus arundinaceus in their ancestry, produced significantly higher biomass than commercial check. Analysis of means showed that hybrids (viz., 99-489, KGS 2004-13, KGS 2004-60, KGS 2004-186, GU 07-3704, KGS 99-100) possess significantly greater bioenergy than experimental mean (461.61 Gj/ha/year). Interspecific hybrids, viz. , GU 07-3704 (37.24 t ha −1 ) and 99-489 (33.25 t ha −1 ) obtained from Saccharum officinarum and S. spontaneum , KGS 2004-13, KGS 2004-60, and KGS 2004-186 from S. barberi and S. sinense produced significantly higher biomass. These clones were also resistant to red rot and borer insects. Cluster analysis revealed genetic diversity present in these species for biomass-contributing traits, which could serve as potential donors for high biomass and bioenergy traits into cultivated canes along with tolerance to abiotic and biotic stresses.

Impact of the improvements inFusarium head blight and agronomic management on economics of winter wheat

Fusarium head blight (FHB) is a devastating disease to cereal crops worldwide that decreases grain yield, grain quality, and causes mycotoxin contamination. FHB resulted in an estimated $2 billion USD loss in the US between 1993 and 2001, and 520 million Canadian dollars (CAD) in Canada in the 1990s. In the wheat producing areas in Canada and the United States, it is perceived that significant progress has been made to manage FHB, but the economic impact of various innovations has not been quantified. Therefore, the main objective of this study was to assess the economic impact of various practices deployed in the province of Ontario, Canada, on managing deoxynivalenol and improving agronomic performance in winter wheat since an epidemic in 1996. The impacts of four hypothetical FHB management scenarios on total deoxynivalenol (DON) concentration and grain yield were estimated in field experiments that compared old (mid-1990s) and modern era (mid-2010s) production practices. Management scenarios included old and new cultivars varying in susceptibility to FHB, fungicide application and nitrogen rates. These impacts were applied to farm survey data collected in 1996 to estimate farm revenue and profit. A similar economic estimate was conducted for the recent FHB epidemic in 2013. If a modern MR cultivar, a modern fungicide, and the combination were deployed in the epidemic of 1996, farm revenue would have increased by 26-32, 23-36 and 48-60%, and profit increased by 88-157, 42-59 and 165-207 CAD per ha, respectively, depending on the nitrogen rate. In the province of Ontario, up to 68 million CAD of revenue losses could have been avoided in 1996 with the use of modern agronomic and FHB management practices. Our study has quantified some of the major economic advances in managing FHB and DON since 1996, but further research is needed to develop better cultivars and management strategies.

Resistance to causal agents of late blight and golden potato nematode of the modern cultivars of seed potatoes and their phytosanitary status in various agroclimatic zones of the European part of Russia

Активная экспансия зарубежных сортов картофеля на территорию Российской Федерации привела к смене доминирующих видов патогенов этой культуры и появлению новых патотипов возбудителей вредоносных болезней. Целью работы была оценка устойчивости к возбудителям фитофтороза и глободероза современного сортимента картофеля и определение поражаемости возделываемых сортов картофеля грибными и оомицетными болезнями в различных агроклиматических зонах России. Проведена оценка устойчивости 41 сорта зарубежной селекции, разрешенного к использованию на территории РФ, к патотипу Ro1 Globodera rostochiensis и к изоляту VZR17 Phytophthora infestans, включающего гены вирулентности 1.2.3.4.5.6.7.8.9.10.11. Устойчивыми к золотистой картофельной нематоде оказались 38 сортов. У 96.6 % изученных нематодоустойчивых сортов выявлен маркер гена Н1 устойчивости к патотипу Ro1 G. rostochiensis, восприимчивые сорта этим маркером не обладали. Абсолютной устойчивостью к возбудителю фитофтороза отличались сорта Alouette и Sarpo Mira (балл 9); высоким уровнем устойчивости (баллы 6 и 7) характеризовались сорта Evolution, Red Fantasy и Ricarda. Сорта Baltic Rose, Damaris, Desiree, Gala, Labella, Laperla, Mia, Sanibel, Zekura, Queen Anne, Red Lady и 7 for 7 были отнесены к восприимчивым, хотя в характеристиках оригинаторов указана средняя устойчивость к фитофторозу. Фитопатологическая экспертиза проведена для 92 образцов 39 сортов семенного картофеля из четырех федеральных округов РФ: Приволжского, Северо-Западного, Центрального и Северо-Кавказского. Наибольшее распространение на всех сортах получили ризоктониоз, сухая фузариозная гниль и серебристая парша. Стопроцентное поражение клубней серебристой паршой отмечено в различных регионах на сортах элитных репродукций Red Scarlett, Evolution, Labella, Colombo, Gala, Невский. Широко распространен антракноз картофеля; сильнее всего были поражены клубни элитной и второй репродукции сорта Red Scarlett – от 50.0 до 71.4 % в Центральном федеральном округе.

Economics of Chickpea Cultivation and Livelihood of Chickpea farmers in Drought-prone Region of Bangladesh

The cultivation of improved chickpea varieties has been increasing over time that kicks off the local varieties from the farmer’s field. In this study, we analyze the difference between the profitability of modern and traditional chickpea varieties as well as assess the livelihood of improved and local chickpea farmers in the high barind region of Bangladesh. The values of benefit-cost ratio depict that the improved variety in more profitable in comparison to local chickpea variety. Meanwhile, the multidimensional livelihood index of the Department for International Development reflects that the modern variety cultivars belong in a better livelihood condition than the local variety growers. Among all the five capitals of the multidimensional livelihood index, the difference between these two groups is the largest in the case of social capital, which is followed by financial capital. In the same way, the former group has higher values for human, physical, and natural capital than their counterparts.

Identification of useful recombinants from interspecific hybrids of Citrullus lanatus and C. colocynthis

Watermelon (Citrullus lanatus) is an important fruit crop in the arid region of western India. The modern watermelon cultivars share a narrow genetic base and are susceptible to various stresses. Thus, there is a need to expand its genetic base through distant hybridization by interspecific crossing with C. colocynthis. An attempt was made to develop interspecific hybrids between lanatus and colocynthis followed by hybridity testing of F1 through SSR markers and biochemical analysis of F2. Out of nine primers, eight primers could successfully show amplification in parents and hybrids out of which two markers could correctly discriminate the true hybrid. The morphological analysis demonstrated that F1 progeny resembles much with C. colocynthis for most of the characters. Biochemical analysis of pulp of selected F2 plants and parents indicated that in many F2 plants biochemicals were higher than parents which suggest that the blending of genes from both species made a favourable effect. Diterpene was only present in watermelon and not detected in C. colocynthis or any of the F2 plants. GC–MS based fatty acid profiling of nine identified fatty acids namely palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid was done. It can be concluded that the interspecific hybrids between water melon and C. colocynthis as also confirmed by molecular markers and superior F2 plants can be used in watermelon breeding program for enhancing vital phytochemicals.

Optimum seeding rate and stand assessment of soft red winter wheat

AbstractCultivar selection and seeding rate influence soft red winter wheat (Triticum aestivum L) grain yield. Re‐evaluating optimum seeding rate for crops is necessary as modern cultivars may show a greater yield advantage when planted at a higher plant population compared with older cultivars. Furthermore, the relationship between wheat stem population density and yield needs to be understood to help producers make informed estimates of yield potential. The objectives of this research were to determine: (a) the agronomic and economic optimum seeding rate (AOSR and EOSR, respectively) of soft red winter wheat, and (b) the relationship of wheat stem population density and grain yield. Trials were established during two growing seasons at two locations in Ohio with four wheat cultivars and four seeding rates ranging from 1.85 to 6.18 million seeds ha−1. Among the four cultivars, the quadratic plateau model resulted in an average AOSR of 4.20 million seeds ha−1 and an average EOSR of 3.13 million seeds ha−1. The AOSR was 10–33% greater than the previous recommendation of 2.96 to 3.95 million seeds ha−1. This increase may be due to modern wheat cultivars having a higher tolerance to increased plant density as the previous recommendation, which is over 30‐yr old. Wheat stem number was linearly related to grain yield and explained 31% of the variability in yield. Planting the optimum number of wheat seeds followed by wheat stand evaluation in the spring should result in maximum economic return and informed decisions regarding wheat yield potential.

Evaluating the effect of agronomic management practices on the performance of differing spelt (Triticum spelta) cultivars in contrasting environments

Abstract Spelt (Triticum spelta) is an ancient wheat which is attracting renewed interest with an increasing demand for wholegrains and ancient cereals in the diet. This study evaluates the yield and quality performance of four contrasting European spelt varieties (both landraces and modern cultivars) grown with different fertiliser types (cattle slurry, farm yard manure, and biogas digestate in comparison with mineral N) and rates (50 and 100 kg N ha−1) in contrasting environments, i.e. the UK and CZ in the 2014−15 and 2015−16 seasons. Grain yield was similar in both seasons but was greater in CZ than the UK (4.9 vs 3.2 t ha−1) which was also supported by a much greater harvest index (HI) of 40.4 vs 31.3 % and all yield components measured. The yield differences were largely related to differences in climate and disease levels, i.e. leaf blotch (S. tritici) and yellow rust (Puccinia striiformis), which were much greater in the UK. Clear varietal differences were evident between the two sites especially in susceptibility to yellow rust. Leaf chlorophyll data showed that the uptake efficiency of the biogas digestate was similar to that of mineral N resulting in greater grain yield when averaged across sites and seasons. Significantly lower levels of yellow rust were observed under the biogas digestate treatment in the UK relative to the other fertiliser types. Clear genotype (G) x environment (E) interactions show the benefits of selecting spelt varieties suited to particular environments. Although yields of spelt are lower than common wheat, the crop benefits from lower inputs of fertiliser and the use of biogas digestate where available can provide a clear opportunity for organic and reduced input growers. The ability of the crop to produce a high grain protein content from low levels of fertiliser input shows the clear potential of spelt production systems whereby wheat in the UK struggles to achieve13 % protein from much greater rates of N fertiliser.

Allelic Variation at the Vernalization Response (Vrn-1) and Photoperiod Sensitivity (Ppd-1) Genes and Their Association With the Development of Durum Wheat Landraces and Modern Cultivars.

Wheat adaptability to a wide range of environmental conditions is mostly determined by allelic diversity within genes controlling vernalization requirement (Vrn-1) and photoperiod sensitivity (Ppd-1). We characterized a panel of 151 durum wheat Mediterranean landraces and 20 representative locally adapted modern cultivars for their allelic composition at Vrn-1 and Ppd-1 gene using diagnostic molecular markers and studied their association with the time needed to reach six growth stages under field conditions over 6 years. Compared with the more diverse and representative landrace collection, the set of modern cultivars were characterized by a reduction of 50% in the number of allelic variants at the Vrn-A1 and Vrn-B1 genes, and the high frequency of mutant alleles conferring photoperiod insensitivity at Ppd-A1, which resulted on a shorter cycle length. Vrn-A1 played a greater role than Vrn-B1 in regulating crop development (Vrn-A1 > Vrn-B1). The results suggest that mutations in the Vrn-A1 gene may have been the most important in establishing the spring growth habit of Mediterranean landraces and modern durum cultivars. The allele Vrn-A1d, found in 10 landraces, delayed development. The relative effects of single Vrn-A1 alleles on delaying the development of the landraces were vrn-A1 = Vrn-A1d > Vrn-A1b > Vrn-A1c. Allele vrn-B1 was present in all except two landraces and in all modern cultivars. The null allele at Ppd-A1 (a deletion first observed in the French bread wheat cultivar ‘Capelle-Desprez’) was found for the first time in durum wheat in the present study that identified it in 30 landraces from 13 Mediterranean countries. Allele Ppd-A1a (GS105) was detected in both germplasm types, while the allele Ppd-A1a (GS100) was found only in modern North American and Spanish cultivars. The relative effect of single Ppd-A1 alleles on extending phenological development was Ppd-A1(DelCD) > Ppd-A1b > Ppd-A1a (GS105) > Ppd-A1a (GS100). Sixteen Vrn-1+Ppd-1 allelic combinations were found in landraces and six in modern cultivars, but only three were common to both panels. Differences in the number of days to reach anthesis were 10 days in landraces and 3 days in modern cultivars. Interactive effects between Vrn-1 and Ppd-1 genes were detected.