25 research outputs found
Effect of reciprocal crossing in partial interspecific lines stability and breeding of commercial varieties in cotton
No full textCotton is one of the most important crops both in Greece and worldwide. Modern demands of producers and industry as well as the needs of the ever-growing tertiary sector, contribute to the creation of competitive cotton varieties which will include all desired traits in one genotype. For this purpose, a production system of partial interspecific cotton lines was developed in the Laboratory of Genetics and Plant Breeding in the Aristotle University of Thessaloniki, originating from the pollination of Gossypium hirsutum x Gossypium barbadense hybrids with pollen from the species Hibiscus cannabinus. This effort eventually led to the isolation of genotypes with relatively high yields and excellent quality characteristics. The aim of this study was the exploitation of this genetic material in breeding experiments for the isolation of superior genotypes combining high yield and fiber quality traits with stability of performance. Initially, a three-year experiment was designed for the evaluation and selection of seven partial interspecific cotton lines. The experiments included the biennial evaluation of cotton lines in the absence of competition, according to honeycomb methodology and then the evaluation of selected genotypes in dense planting. The result of this effort was the identification of genotypes with stable performances (increased emergence capacity, morphological uniformity, and increased earliness), high yield and good fiber quality traits compared to commercial varieties that were used as controls. Besides, partial interspecific cotton lines were included in a program of reciprocal backcrosses with commercial cotton varieties aiming to improve the quality characteristics of commercial varieties and to increase the stability behavior of partial interspecific lines. The backcrosses were applied for three years and the progeny were evaluated separately in the absence of competition in two experiments (honeycomb designs R-13 and R-16). The selected genotypes were evaluated for another two years in dense planting. In general, the backcrosses of partial interspecific lines with commercial varieties seem to lead to some high-yielding genotypes with stable performance but slightly lower values for the fiber attributes compared to initial partial interspecific lines. Finally, the repeatability of the protocol used for the production of the partial interspecific hybrids through the pollination of the Gossypium hirsutum x Gossypium barbadense hybrids with pollen from the species H.cannabinus using new combination of commercial varieties as parents was checked and verified. This methodology creates new genetic variation since it leads to the effective integration of the genetic material of two species in one genotype, avoiding problems of previous methodology. Furthermore, SSR molecular markers were used for the molecular identification of the partial interspecific lines obtained and the study of the phylogenetic relationships among the partial interspecific hybrids, their respective parents, the F1 and F2 generations and their progeny Pa0 and Pa1. The results indicate that partial interspecific lines genetically differ from the products of self-pollination of the F1 interspecific hybrid.Το βαμβάκι αποτελεί μία από τις σημαντικότερες καλλιέργειες, τόσο στην Ελλάδα, όσο και σε παγκόσμιο επίπεδο. Οι σύγχρονες απαιτήσεις των παραγωγών και της βιομηχανίας, καθώς και οι ανάγκες του συνεχώς αναπτυσσόμενου τριτογενούς τομέα, συμβάλλουν στη δημιουργία ανταγωνιστικών ποικιλιών βαμβακιού, που θα συμπεριλαμβάνουν όλα τα επιθυμητά γνωρίσματα σε έναν γενότυπο. Στο Εργαστήριο Γενετικής και Βελτίωσης Φυτών του Αριστοτελείου Πανεπιστημίου Θεσσαλονίκης αναπτύχθηκε ένα σύστημα παραγωγής μερικώς διειδικών φυτών βαμβακιού, προερχόμενων από την επικονίαση υβριδίων Gossypium hirsutum x Gossypium barbadense με γύρη από το είδος Hibiscus cannabinus. Η προσπάθεια αυτή οδήγησε στην απομόνωση γενοτύπων με υψηλές αποδόσεις και άριστα ποιοτικά χαρακτηριστικά. Σκοπός της συγκεκριμένης εργασίας ήταν η αξιοποίηση του εν λόγω γενετικού υλικού σε πειράματα βελτίωσης, που θα οδηγήσουν στον εντοπισμό υπέρτερων γενοτύπων, οι οποίοι συνδυάζουν την υψηλή απόδοση και την εξαιρετική ποιότητα ίνας με τη σταθερότητα της συμπεριφοράς. Αρχικά, σχεδιάστηκε ένα τριετές πείραμα αξιολόγησης και επιλογής, με υλικό εκκίνησης επτά μερικώς διειδικές σειρές βαμβακιού. Τα πειράματα συμπεριλάμβαναν τη διετή αξιολόγηση των σειρών, σε κυψελωτή διάταξη, απουσία ανταγωνισμού, και στη συνέχεια την αξιολόγηση των γενοτύπων που διακρίθηκαν, σε συνθήκες πυκνής σποράς. Το αποτέλεσμα της προσπάθειας αυτής ήταν η εκκαθάριση του αρχικού γενετικού υλικού, που οδήγησε στην απομόνωση γενοτύπων με σταθερότητα παραγωγικής συμπεριφοράς (αύξηση της φυτρωτικής ικανότητας, μορφολογική ομοιομορφία, αύξηση πρωιμότητας), υψηλές αποδόσεις και εξαιρετική ποιότητα, σε σχέση με τις εμπορικές ποικιλίες-μάρτυρες. Παράλληλα, οι μερικώς διειδικές σειρές βαμβακιού συμπεριλήφθησαν και σε ένα πρόγραμμα αμοιβαίων αναδιασταυρώσεων με εμπορικές ποικιλίες βαμβακιού, με σκοπό τη βελτίωση των ποιοτικών χαρακτηριστικών των εμπορικών ποικιλιών και την αύξηση της σταθερότητας συμπεριφοράς των μερικώς διειδικών σειρών. Οι αναδιασταυρώσεις εφαρμόστηκαν για τρία έτη και οι απόγονοι των αναδιασταυρώσεων αξιολογήθηκαν ξεχωριστά, απουσία ανταγωνισμού, σε δύο πειράματα (κυψελωτή διάταξη R-13 και R-16, αντίστοιχα). Οι γενότυποι που επιλέχθηκαν αξιολογήθηκαν τελικά για δύο έτη, σε συνθήκες πυκνής σποράς. Σε γενικές γραμμές, οι αναδιασταυρώσεις των μερικώς διειδικών σειρών με τις εμπορικές ποικιλίες φαίνεται να οδηγούν σε ορισμένους υψηλοαποδοτικούς γενοτύπους, με ελαφρώς χαμηλότερες τιμές για τα γνωρίσματα της ίνας σε σχέση με αυτές που παρουσίαζαν οι μερικώς διειδικές σειρές, αλλά με υψηλότερη σταθερότητα συμπεριφοράς. Τέλος, ελέγχθηκε και επιβεβαιώθηκε η επαναληψιμότητα του πρωτοκόλλου παραγωγής των μερικώς διειδικών υβριδίων μέσω της επικονίασης υβριδίων Gossypium hirsutum x Gossypium barbadense με γύρη από το είδος H. cannabinus, επιλέγοντας νέους συνδυασμούς ποικιλιών ως γονείς. Η συγκεκριμένη μεθοδολογία δημιουργεί νέα γενετική παραλλακτικότητα, αφού οδηγεί στην αποτελεσματική ενσωμάτωση του γενετικού υλικού των δύο ειδών σε έναν γενότυπο, χωρίς τα προβλήματα που παρουσιάζουν οι παλαιότερες μεθοδολογίες. Επίσης, χρησιμοποιήθηκαν μοριακοί δείκτες τύπου SSR για τη μοριακή ταυτοποίηση των μερικώς διειδικών σειρών που προέκυψαν, και τη διερεύνηση των φυλογενετικών σχέσεων ανάμεσα στα μερικώς διειδικά υβρίδια, τους αντίστοιχους γονείς, τις F1 και F2 γενεές, αλλά και τους απογόνους Pa0 και Pa1. Τα αποτελέσματα αποτελούν ένδειξη ότι τα μερικώς διειδικά υβρίδια διαφέρουν γενετικά από τα προϊόντα της αυτογονιμοποίησης του συγκεκριμένου υβριδίου (F1 γενεά)
Interaction of cultivar and irrigation on mixtures of wheat (Triticum aestivum L.) with pea (Pisum sativum L.)
No full textDOI: 10.15835/nbha49412488
Intercropping is the simultaneous cultivation of two or more crops species in the same space for a considerable proportion of the growth period. Intercropping has several advantages and is used in both traditional and sustainable agriculture. The objective of the present study was to study the interactions among different pea and wheat cultivars and the effect of water availability on wheat-pea mixtures and the competition between the two species. The experiment was conducted for two successive growing seasons using two different irrigation regimes and two cultivars from each species. The different treatments were evaluated using morphological and agronomic characteristics. Intercropping treatment, cultivars, and irrigation level affected most of the characteristics that were studied and the competition between the two species. Biomass was higher by 47% and leaf area index by 34% under irrigation compared to the rainfed conditions. The different cultivars showed different response under the two water regimes. Based on the intercropping indices, the mixture ‘Yecora E’ - ‘Isard’ is favoured under irrigation while the combination ‘Elissavet’ - ‘Isard’ under low water availability. There was interaction between cultivars and irrigation and using different cultivars in intercropping can have higher yield advantage than monocropping by exploiting the environmental resources more efficiently. Therefore, the use of appropriate cultivars in mixtures can affect the growth, biomass yield and competition between the two species leading to higher yield and greater economic return
Intercropping grain-legumes and cereals for improved protein concentration in the cereal (ReMIX Practice Abstract)
No full textOutcome:
Mixed cropping systems achieve higher protein content of bread wheat, with no need to include nitrogen (N) fertilizers.
Practical recommendations:
- The seed bed should not be too fine-grained after cultivation.
- Test soil samples and amend P and K levels, if necessary.
- Select cultivars (wheat and grain legume) with the same maturity time according to local seed costs and market availability.
- Mix the seeds 70% grain legume and 30% wheat relative to the standard sowing quantities of the crops in the seed tank. Check that the mixture is homogenous and sow with a conventional seeder.
- Use the recommended row spacing of the cereal crop.
- Apply weed control as needed (organic or conventional).
- Adjust the height of the harvester to pick up grain legumes close to ground.
Practical testing/ Farmers’ experiences:
If this crop system seems suitable for you, we recommend that you test this under your conditions. Separate a part of your field before sowing and apply the mixture. Cultivate the rest of the field as usual and compare the intercrop to the pure stand cereals and/or legumes crops
Effect of Irrigation on Intercropping Systems of Wheat (<i>Triticum aestivum</i> L.) with Pea (<i>Pisum sativum</i> L.)
No full textIntercropping is an old and commonly used agricultural practice and involves the cultivation of two or more crops in the same area of land at the same time and may improve yield, the use of the environmental resources, product quality, and soil health. The objective of the present study was to study the effect of water availability of wheat-pea intercrops using agronomic and physiological characteristics. The experiment was conducted at the farm of Aristotle University of Thessaloniki, Greece during two growing seasons 2017–2018 and 2018–2019 using two different cultivars from pea (Isard and Olympos) and wheat (Yecora E and Elissavet) and two irrigation regimes. The availability of water increased grain yield and affected most of the characteristics that were studied. In terms of total Land Equivalent Ratio (LER) there was a yield advantage of intercrops over monocrops, which indicates the efficiency of intercropping for using the environmental resources. Both wheat cultivars, the pea cultivar Olympos and their intercrops indicated high adaptation capacity to rainfed conditions, whereas Isard and its intercrops performed better under irrigation. Therefore, the intercropping of wheat with pea uses the water resources of the environment more efficiently and can be used in dry land conditions for higher yield
Importance of Selection of Cultivars in Wheat–Pea Intercropping Systems for High Productivity
No full textIntercropping is the cultivation of two or more crop species in the same space for a considerable proportion of the growth period. Farmers use cultivars that were bred under monoculture and there are no cultivars that have been evaluated under intercropping systems. The objective of the present study was to evaluate different cultivars of pea and wheat on intercropping systems. The experiment was conducted for two successive growing seasons (2018–2019 and 2019–2020) at the University Farm of Aristotle University of Thessaloniki, Greece, using two cultivars of field pea and six cultivars of bread wheat, and all their mixture combinations. The growing seasons, the intercropping treatments, and the cultivars affected the grain yield, the yield components, and the land equivalent ratio (LER) and actual yield loss (AYL) values. The different cultivars showed different responses under the intercropping treatments, indicating that there are cultivars that show higher grain yield in mixtures. Based on the mean grain yield for both growing seasons, the mixture ‘Isard’–‘Mavragani’ showed higher grain yield by 86.5% and 55.7% compared with the mean grain yield of all other mixtures and monocultures, respectively. The total LER value of ‘Isard’–‘Mavragani’ was high in both years: 1.954 and 1.693 in 2018–2019 and 2019–2020, respectively. This multicriteria evaluation of winter wheat and field pea varieties exhibited the need for the selection of appropriate cultivars for intercropping systems that were previously assessed under intercropping conditions before their exploitation from the farmers
Effect of Cultivar on Faba Bean–Wheat Intercrop Productivity under a Mediterranean Environment
No full textThe term intercropping is used to describe agricultural systems where at least two or more species are cultivated in the same field for a portion of their biological cycle. It is an ancient agricultural practice that, with the evolution of agriculture, the prevalence of intensive cultivation systems, and the use of multiple inputs became mostly restricted to developing countries. However, due to climate instability and uncertainty about weather conditions, interest in intercropping has been revived in recent years. The objective of the present study was to determine which faba bean cultivar can be used with wheat cultivars to achieve higher yields and to examine the interaction between the cultivars in intercropping systems. It was found that the combination of Flamenko with Polycarpi gave the highest yield and showed complementarity in the interaction between these cultivars that also have the highest yield; also, the other indices that were used showed a good response on the intercropping system and the LER was 1.30 and 1.19 for the first and the second year of the study, respectively. Therefore, there are faba bean and wheat cultivars that are better adapted to intercropping conditions and can be utilized by farmers to enhance productivity
Testing Taylor's Power Law association of maize interplant variation with mean grain yield
No full textPlant-to-plant variability is a crop stability component. The objective of this study in maize (Zea mays L.) was to test the validity of the theoretical background of the hypothesis that the coefficient of variation (CV) for grain yield per plant and mean yield are connected exponentially, following the Taylor's Power Law (TPL) Model. Field experimentation was conducted across two sites, two seasons, and two planting densities. Densities were the main plots, corresponding to the typical practice of 8.89 plants m–2 (TCD) and the low-input optimal of 5.33 plants m–2 (LCD), while hybrids were the subplots. Data from 26 subplots in the first site averaged CV values of 22.6% at the TCD and 21.9% at the LCD, and mean yields of 19.1 and 13.9 t ha–1, respectively, following the TPL Model. The same was true for the second site, with average CVs and means of 41.5% and 14.3 t ha–1 at the TCD and 36.8% and 11.5 t ha–1 at the LCD. A test was performed on the simple correlation between the logarithms of variances and their respective means to investigate whether there is a systematic variance dependence on mean, thus questioning the reliability of TPL. The validity of TPL was verified in the first site. Nevertheless, there was a systematic dependence of yield variance on mean yield in the second site, implying that the CV-yield correlation might be not biologically meaningful. Conversion of the variance to remove its dependence on the mean did not validate the CV-yield negative relationship, meaning that caution is needed when interpreting the CV as a stability index for intra-crop variation. Whether the determinant factor of invalidity of TPL was the extensive intra-crop variation in the lower yielding second site can be assessed in future research
Factors Connected with the Registration of “Sikali Vevis” as a Geographical Indication Protection (PGI) Product
No full textThe rate of rye consumption is increasing due to its benefits for human health. “Sikali Vevis” is a cultivated traditional rye population of the Vevi area, Florina of Western Macedonia, Greece, which supports the local agricultural community. However, the identity of this traditional population is not yet protected. This work, funded under the Agricultural Development Program 2014–2020 (Measure 16), Sub-Measure 16.1–16.2 (project Μ16SYN2-00321), will present the parameters connected with the description of the unique identity of this product, its origin, its traceability, local agricultural practices, and specific characteristics that will contribute to the protection of this traditional population
Seed Rate and Cultivar Effect on Contribution of <i>Vicia sativa</i> L. Green Manure to Soil Amendment under Mediterranean Conditions
No full textThe performance of Vicia sativa L. cultivars and cultivar mixtures used as green manure under two seed rates in a Mediterranean environment was investigated in a split plot design, over the period 2014–2016. Six common vetch cultivars grown in pure stands or in mixtures were established at two seed rates (S1 = 100 Kg ha−1 and S2 = 180 kg ha−1). Growth traits (e.g., plant height, biomass yield, LAI, CGR) were monitored until incorporation into topsoil. The nitrogen (N) concentration of the incorporated biomass along with the decomposition rate were determined, and the effects on the N supply to the soil were evaluated two, four and six months after biomass incorporation. The increment in residual soil Ν four months after green manuring fluctuated from 17 to 45 kg ha−1 among cultivars, and after six months, from 22 to 50 kg ha−1. The average decomposition rate of organic substances was slightly higher for S2 for all time intervals; however the highest value (62.6%) was recorded for S1 six months after biomass incorporation. Seed rate-independent genotypes were identified with regard to the decomposition of organic matter and are suggested as being suitable for green-manuring farming systems with a low seed rate, a fact that offers options with economic and environmental benefits
Testing the Validity of CV for Single-Plant Yield in the Absence of Competition as a Homeostasis Index
No full textThe coefficient of variation (CV) of yield may functionally be related to the mean. The expected exponential CV decline with increasing mean, i.e., the Taylor’s power law (TPL), is not always valid. Removal of this scale dependency allows for a scale-independent assessment of stability. The objective of this study was to interpret the validity of the homeostasis index (HI), i.e., the inverse CV value, suggested in breeding under nil competition as a selection criterion for progeny lines that oppose the acquired interplant variation. Data concerning the single-plant yield of various crops under a nil-competition regime were studies against the theoretical background of the above hypothesis. Simple correlations between logarithms of variances and respective means were used to assess the reliability of CV as a stability statistic in breeding trials under nil competition. A total of 8 of the 24 case analyses revealed a systematic variance dependence on the mean. The impact was more prevalent in experiments with extensive spatial heterogeneity and high CV scores. Conversion of variance to remove systematic dependence did not validate the CV~mean negative relationship. Because of variance dependence, caution is needed when interpreting the HI as a stability index. Misuse of the HI may entail the risk of bias, upgrading or downgrading a progeny line in its ability to withstand acquired dissimilarity between plants. Testing the validity of the variance seems necessary, and the calculation of HI on a converted variance may enhance the accuracy of identifying the most promising progeny lines
