Alterations in growth of maize seedlings influenced by mixed tetraoxanes

Application of natural or synthetic substances could increases maize vigor, particularly of seeds with poor viability. The aim of this experiment was to examine the influence of five mixed tetraoxanes (T1–T5) on germination and early growth (seven day old seedlings) of maize inbred line, from the lot with high germination ability (>90%-G1) and low germination ability (<50%-G2). After soaking in tetraoxanes solution (10-6 and 10-9 M) for 24h, at room temperature, the seeds were germinated under controlled laboratory conditions on filter paper (BP, 20⇔30°C, ISTA Rules). Results show diverse effects of applied treatments. The significant increase in germination of 21.3% (10-9 M) for G2, as well as in seedlings roots and shoot fresh biomass for both lots, were observed in T1 treatment. The highest increase of seedlings root and shoot dry matter (8.79% and 8.08% for G1, as well as 9.52% and 8.99% for G2, respectively) was obtained by T4 treatment. For G1, increased seedlings root to shoot ratio for fresh matter, was achieved with T4 (10-9 M), while for G2, T3 brought the highest values of the ratio for both fresh and dry matter. For G1, increased seedlings root to shot ratio for dry matter was achieved under T4 (10-9 M). All applied treatments increased hydrolysis and biosynthesis. The highest hydrolysis values for G1was achieved by T2 (0.1640 g) and for G2 by T1 treatment (0.1187 g). The highest values of biosynthesis were achieved under T4 for both G1 and G2 (0.0723 and 0.0426 g, respectively). For G2, interdependence between germination and seedlings root and shoot fresh matter, and between hydrolysis and biosynthesis, implied a significant and negative correlation between germination rate and root fresh matter. Moreover, significant increase in germination rate for G2 was followed by increase in seedlings root and shoot fresh matter, hydrolysis and biosynthesis

Biofortification – important part of agricultural practice

Biofortifikacija predstavlja čitav kompleks mera koje obuhvataju selekcionisanje novih genotipova, manipulacije genima, različite mere gajenja kojima se omogućava bolja apsorpcija i povećana akumulacija esencijalnih elemenata, kao što su gvožđe, cink, mangan, bakar i dr. u jestivim delovima gajenih biljaka. Pored toga, nezaobilazni deo biofortifikacije predstavlja i unapređenje faktora koji povećavaju apsorpciju mikroelemenata, a eliminisanje faktora koji ometaju njihovu apsorpciju i time smanjenje antinutritiva. Rezultati su pokazali da je u semenu linija koje pripadaju Lankaster heterotiĉnoj grupi povećanje sadrţaja Zn bilo praćeno padom fitata, dok veći sadrţaj β-karotena u semenu BSSS genotipova može poboljšati apsoprpciju Mn i Zn. Neke linije kukuruza iz Banke gena imaju povećanu pristupačnost Mg, Fe, Mn i Zn, zahvaljujući nižem odnosu fitat/β-karoten i mogle bi se iskoristiti u selekciji fortifikovanih hibrida kukuruza. U semenu nekih populacija, variranje u sadržaju Fe i Zn je nezavisno od inhibitora i promotera. Održiva proizvodnja koja obuhvata kombinovane ili pokrovne useve može da poboljša apsorpciju i akumulaciju esencijalnih elemenata u zrnu kukuruza i soje. Tako, u zrnu soje gajene u kombinaciji s kukuruzom, β-karoten je osnovni faktor koji doprinosi Fe pristupačnosti. Naizmenični redovi u kombinaciji s bio-đubrivom doprinose povećanoj Fe i Mg pristupačnosti, kao i boljem iskorišćenju uslova, povećavajući plodnost zemljišta soje i kukuruza. U eksperimentima s pokrovnim usevima, kombinacija organskog malča i bio-đubriva se pokazala kao najefikasnija za poboljšanu pristupačnost Mg i Zn iz zrna kukuruza šećerca, dok su stočni grašak i ozimi ovas najefikasnija kombinacija za poboljšanu Fe pristupačnost. Određena bio- i organska đubriva mogu povećati nivo β-karotena, a smanjiti nivo fitata u zrnu kukuruza, povećavajući pristupačnost esencijalnih elemenata.Biofortification represents complex of different measures that include new genotypes breeding, gene manipulations, different cropping measures which enable better absorption and accumulation of essential elements, like iron, zinc, manganese, copper, etc. in edible plant parts. Besides, increase in factors that promote microelements absorption, as well as reduction in antinutritives (factors that supress microelements absorption) represent unavoidable part of biofortification. Results showed that Zn increase is followed by reduction in phytate content, particularly in maize lines from Lancaster heterotic group, while increased β-carotene content could improve Mn and Zn availability from grain of BSSS genotypes. Some maize lines from Gene bank were characterised with increased Mg, Fe, Mn and Zn availability, owing to low phytate/β-carotene ratio. They could be used in breeding for production of fortified maize hybrids. In grain of some landraces, variations in Fe and Zn content are independent of variations in inhibitor and promoter contents. Sustainable practices, like intercropping or application of cover crops could improve absorption and accumulation of essential elements in maize and soybean grain. For instance, in grain of intercropped soybean β-carotene is the main factor contributing to Fe availability. Alternating rows in combination with biofertilizer emphasised increased Fe and Mg availability and better utilization of the conditions and the soil fertility under the both, maize and soybean. In experiments with cover crops, organic mulch+biofertilizer expressed the highest efficiency for improved Mg and Zn bioavailability from sweet maize kernel, while field pea+winter oats was the most effective for improved Fe bioavailability. Some biofertilizers and organic fertilizers could increase β-carotene level and decrease phytate concetration in maize grain, thus increasing bioavailability of essential elements

Adaptation of food production systems to global changes

Agricultural plants, mainly for food production are prone to variability of agro-ecolog ical conditions, particularly to meteorological conditions.Relatively frequent meteo rological extremes are reflecting negatively on agro-ecosystem, depleting soil fertility and raising its erosion, spreading invasive weeds, hard to control, thus reducing rapidly arable areas. At the same time, meteorological extremes are diminishing production of agricultural plants, their yields, as well as quality, reflecting negative on food security. It is well known that reduced yields of staple crops, like wheat, maize, rice and others are present in drier seasons, while increased concentration of protein, some vitamins and antioxidants is pres ent at the same time. However, in the most of the cases higher infestation with pathogenic fungus is present, thus increasing mycotoxines level. Meteorological extremes are mainly driven by anthropogenic factors, which are also responsible for reduced quality of agri cultural products. For example, globalisation trends mirrored through “Green revolution” were conceptualised to resolve worldwide hunger, by introducing of high yield genotypes, prone to stressful conditions, together with high inputs of water, mineral fertilizers (mainly based on nitrogen, phosphorus and potassium) and other toxic agro-chemicals, impairing agro-ecosystem by reduction of biodiversity, depleting of soil fertility through decrease of organic matter, microbiome diversity and particularly micro-elements, important for both, plants and humans, thus contributing to the low quality of produced food, i.e. hidden mal nutrition. Worldwide present malnutrition with essential minerals and vitamins contrib utes to the rapid increase of chronic diseases, such as inflammation, metabolic syndrome, diabetes, cardio-vascular diseases, cancer, variety of auto-immune conditions, etc. even to the pandemic level.One of the important facts lies in depletion of phosphorus deposits, leaving agriculture without the main source of this essential mineral. Novel trends that in troduce recycling, usage of alternative, renewable and less used sources of plant nutrients and energy, from the point of rationalisation, together with breeding of genotypes tolerant to various abiotic and biotic stressors, such as meteorological extremes, plant pathogens and low inputs could contribute not just to increased security of plant production, but also to increased quality of agricultural product

The effect of some mixed tetraoxanes on germination and antioxidants in maize seedlings

Germination is one of the most sensitive phases in growth of agricultural plants, where optimal conditions in temperature and water accessibility are required. Seedlings are particularly sensitive to environmental stressors, especially when maize lines are considered. They tend to germinate and grow slower, have poorer adaptability to stress and seeds could lose germination ability relative fast. Application of natural or synthetic substances could increases maize vigor, particularly of seeds with poor viability. It is proven that some stimulators positively affect growth, water absorption and antioxidative response of plants [1-4]. The aim of experiment was to examine the influence of four mixed tetraoxanes on germination and early growth (seven-day old seedlings) of maize inbred line with low germination ability (<50%)

Genetic and phenotypic evaluation of european maize landraces as a tool for conservation and valorization of agrobiodiversity

The ECPGR European Evaluation Network (EVA) for Maize involves genebanks, research institutions, and private breeding companies from nine countries focusing on the valorization of maize genetic resources across Europe. This study describes a diverse collection of 626 local landraces and traditional varieties of maize (Zea mays L.) from nine European genebanks, including criteria for selection of the collection and its genetic and phenotypic diversity. High-throughput pool genotyping grouped the landraces into nine genetic groups with a threshold of 0.6 admixture, while 277 accessions were designated admixed and likely to have resulted from previous breeding activities. The grouping correlated well with the geographic origins of the collection, also reflecting the various pathways of introduction of maize to Europe. Phenotypic evaluations of 588 accessions for flowering time and plant architecture in multilocation trials over three years confirmed the great diversity within the collection, although phenotypic clusters only partially correlated with the genetic grouping. The EVA approach promotes conservation of genetic resources and opens an opportunity to increase genetic variability for developing improved varieties and populations for farmers, with better adaptation to specific environments and greater tolerance to various stresses. As such, the EVA maize collection provides valuable sources of diversity for facing climate change due to the varieties’ local adaptation

Application of different methods for measuring carotenoid status in maize grain

Maize grain carotenoids are among the most abundant in cereals, exhibiting considerable diversity in the composition profiles. In this experiment, HPLC-DAD was used for lutein and zeaxanthin (predominant carotenoids) and β-carotene (proVA carotenoid) determination in flour of whole maize kernel. In addition, Raman spectroscopy, as a non-destructive method for pretreatment-free and rapid in situ screening of carotenoids status in different kernel regions, was applied. Six yellow maize inbred lines (L1-L6) were evaluated. After the spectral normalization, deconvolution was performed on three individual bands in three observed regions on kernel longitudinal section (aleurone cell layer, floury and vitreous endosperm), for all genotypes. It was found that the mean fitted area and intensity of three main carotenoid bands were the highest at 1520 cm-1, medium at 1155 cm-1 and the lowest for the band at 1007 cm-1, as spectral features used to identify carotenoids and quantify relative carotenoid concentration. Both the highest values for mean band fitted area and intensity observed in the floury endosperm, and the lowest in the aleurone cell layer, were recorded in the same regions for all genotypes evaluated. L1 and L2 exhibited the highest values, while L3 and L4 exhibited the lowest values for the average and total band area. Significant and negative correlation between carotenoid content quantified by HPLC-DAD and bands area fit for vitreous endosperm region obtained by Raman spectroscopy (-0.847; p≤0.05), and between carotenoid content and total bands area (-0.898; p≤0.05) indicated the competition for carbon supplies reflected through increased starch reposition over carotenoids accumulation

GENETIC DIVERSITY IN MAIZE FLINT LANDRACES ASSESSED BY MORPHOLOGICAL AND SSR MARKERS

Maize landraces represent potential sources of favorable traits for current and future breeding programs.. A comparative characterization of twenty-one flint maize landraces from Maize Research Institute "Zemun Polje“ gene bank was achieved by using morphological traits and SSR markers. Applied marker systems revealed high level of genetic heterogenity beetween landraces. Cluster analysis of the tested genotypes was based on average values of eighteen observed phenotypic traits. Ten SSR probes revealed total of 68 alleles. Genetic distance between pairs of landraces ranged from 0.05 up to 0.98. Cluster analysis of morphological and SSR markers distances did not exhibited the same grouping of accessions. Individual application of marker systems did not confirm differentiation of certain landraces into a particular agro-ecological group, as was expected according to their origin data. The best way for achieving the most accurate assessment of genetic diversity should comprise parallel application of both approaches

Efficiency of Biological Typing Methods in Maize Hybrid Genetic Purity Estimation

A high level of genetic purity in crop varieties must be achieved and maintained for agronomic performance, encouraging investment and innovation in plant breeding and ensuring that the improvements in productivity and quality imparted by breeders are delivered to the consumer. Since the success of hybrid seed production is dependent upon the genetic purity of the parental lines, in this study, the experimental F1exp maize hybrid and its parental inbreeds were used as a model system to examine the discriminative power of morphological, biochemical and SSR markers for seed purity assay. The highest number of off-type plants was estimated by morphological markers. According to the comparison of prolamins and albumins banding patterns of parental and derived F1exp seeds, genetic impurities could not be detected. Molecular analysis detected two types of genetic profile irregularity. Beside its use for verifying varieties of maize, report on umc1545 primer pair ability to detect non-specific bands (i.e., off-types), in both the maternal component and F1exp, which is the first report on this issue yet, strongly supports the recommendation of this SSR marker use for more accurate and time-efficient maize hybrids and parental lines genetic pyrity testing