Determinação de alterações morfológicas durante a maturação de sementes de melão com uso de raios X

The search for melon with high physiologic quality is essential to have competitive material compared to the imported. The analysis of images realized through X-ray is a technique that verify internal morphology and relates with the seed performance. In this way, the goal of this study was to evaluate the seed physiological quality from melon of Anton cultivar in function of different phase of maturation of stored and non-stored fruits through the visualization of internal morphology of seeds using X-ray images. The experiment was managed from December of 2016 to February of 2018. The yellow-melon fruits analyzed were cultivated in Embrapa Hortaliças greenhouse. The fruits were picked in five distinct periods: 30, 45, 60, 75, and 90 days after anthesis (DAA). In each period were picked a total of 30 fruits where 15 fruits had their seeds immediately extracted after been picked, and 15 fruits were stored. The 15 fruits stored were packed in plastic box properly identified for a period of fifteen days in airy place with room temperature. The 30 fruits were subjected to the same process of seed extraction, washing and drying. The dried seeds from stored and non-stored fruits were submitted to the following analyses: X-ray test and the germination test. The treatment of 60 DAA over storage shown better performance with 67% in the germination test on the first counting and 87% of normal seedlings. This result is similar to the noted in the X-ray test where the treatment demonstrated 96% of filled seeds showing the viability of this tool to determine physiologic quality in the melon seeds.

Wiregrass (Aristida beyrichiana) survival and reproduction after fire in a long-unburned pine savanna

Restoring fire regimes is a major goal of biodiversity conservation efforts in fire-prone ecosystems from which fire has been excluded. In the southeastern U.S.A., nearly a century of fire exclusion in pine savannas has led to significant biodiversity declines in one of the most species-rich ecosystems of North America. In these savannas, frequent fires that support biodiversity are driven by vegetation-fire feedbacks. Understory grasses are key components of these feedbacks, fueling the spread of fires that keep tree density low and maintain a high-light environment. When fire is reintroduced to long-unburned sites, however, remnant populations of bunchgrasses might experience high mortality from fuel accumulation during periods of fire exclusion. Our objective was to quantify fire effects on wiregrass (Aristida beyrichiana), a key component of vegetation-fire feedbacks, following 16 years without fire in a dry pine savanna typically considered to burn every 1–3 years. We examined how wiregrass size and fuel (duff depth and presence of pinecones) affected post-fire survival, inflorescence and seed production, and seed germination. Wiregrass exhibited high survival regardless of size or fuels. Probability of flowering and inflorescence number per plant were unaffected by fuel treatments but increased significantly with plant size (p = 0.016). Germination of filled seeds was consistent (29–43%) regardless of fuels, although plants in low duff produced the greatest proportion of filled seeds. The ability of bunchgrasses to persist and reproduce following fire exclusion could jumpstart efforts to reinstate frequent-fire regimes and facilitate biodiversity restoration where remnant bunchgrass populations remain.

Morphology of strobili at different development positions and cone and seed characteristics of Pinus densiflora f. multicaulis

Pinus densiflora f. multicaulis is a rare and unusual form of genus Pinus. It has excellent ornamental values due to many trunks from its root collar, and produces female, male, and bisexual strobili on thes ame tree. However, there is limited study whether the bisexual strobili are functional, mature lateral conesproduce filled seeds, and the seeds from the mature lateral cones germinate and grow as well as those frommature apical cones. The structure of apical female, and lateral male and bisexual strobili were analyzed in an open-pollination-progeny population. The strobili were photographed to obtain external, cross-section, and radial-section images using a 45× stereoscopic microscope. Radial sections of strobili were imaged using scanning electron microscopy. Characteristics of apical and lateral cones and seeds were surveyedby cone analysis and germination test. P. densiflora f. multicaulis developed typical female strobili apically,and ordinary male and bisexual strobili laterally. Additionally, female strobili developed laterally whereas the male strobili were normally located. The mature lateral female strobili had the same structure as the apical female. In the mature bisexual strobili, the proportion of male and female tissue was unequal. The cones developed from lateral female strobili showed highly significant differences in the length, width, and weight, being shorter (32.7%), narrower (26.9%), and lighter (59.8%) than those from apical female strobili. Both types produced filled seeds and seedlings, and well significant positive correlations were found among characteristics of seeds from apical and lateral female strobili. The initial seed germination rate of the seeds from apical female strobili was higher than that of seeds from lateral female strobili, but the difference decreased over time. The viability and spatial distribution of the female and male tissue of bisporangiate cones, and their frequent occurrence suggests a common mechanism for the production of bisporangiate structures in seed plants.

Genetic variability and selection criteria of some sunflower genotypes under different pollination methods

<p>To determinate self-compatible genotypes for increasing autogamy yielded, the ten sunflower genotypes were sown under four pollination methods i.e., open-, self-, hand- and sib-pollinations in a randomized complete block design replicated thrice at Kafr-El-Hamam Agricultural research Station, Sharkia Governorate, Agricultural Research Center, Egypt during 2018 and 2019 summer seasons. Significant variation existed for different pollination treatments, genotypes and their interactions for all studied traits. Among the treatments, open pollination followed by sibbing one was regarded as the best pollination treatment for head diameter, number of filled seeds per head, percentage of seed setting , kernel to hull ratio, seed mass per plant, seed yield per fed and seed oil content. Autogamy studies revealed that ‘L120’ followed by ‘L92’ and ‘L880’ recorded higher proportion of autogamy and self-compatibility. Preferred improvement of seed mass per plant may be achieved through selecting genotypes having the largest head diameter, bigger number of filled seeds per head, the highest proportion of seed setting and the heaviest seed, kernel and hull mass as proven by high phenotypic and genotypic coefficient of variation and high heritability coupled with high genetic advance (as % of mean) as well as correlation and path analyses at both phenotypic and genotypic levels.</p>

Genetic Divergence and Variability Studies for Yield and Quality Traits in Elite Rice (Oryza sativa L.) Genotypes

Genetic divergence and variability was assessed among 33 elite germplasm lines which were evaluated in RBD at Regional Agricultural Research Station, Warangal with an objective to classify and understand the nature and magnitude of genetic diversity and variability with regard to grain yield, yield components and quality traits using Mahalanobis D2 statistics. Genotypes were grouped into eight clusters and cluster I was the largest comprised of 23 genotypes followed by cluster II which consists of 4 genotypes and rest of the clusters from cluster III to cluster VIII contain one genotype each. The maximum cluster distance was found between cluster II and cluster IV (2178.98) followed by cluster III and cluster VIII (2160.16). The minimum inter cluster distance was observed between cluster I and cluster III (540.96). The intra cluster distance was maximum for cluster II (354.1) indicating existence of variability within the cluster. A perusal of results on cluster means revealed that cluster VIII recorded highest cluster mean for yield/plant, panicle length, test weight, plant height, volume expansion ratio, kernel length after cooking, length/breadth ratio, kernel length and kernel width, The most important trait causing maximum divergence was plant height (31.8) which ranked 168 times first followed by alkali spreading value, days to 50% flowering and test weight were responsible for differentiating the genotypes studied. Phenotypic coefficient of variation (PCV) was slightly higher than genotypic coefficient of variation (GCV) for all the traits. Moderate GCV and PCV estimates were observed for filled seeds/panicle, test weight, alkali spreading value, volume expansion ratio, yield/plant, water uptake and head rice recovery. High heritability coupled with moderate genetic advance as percent of mean was observed for test weight (98.5:46.62), filled seeds/panicle (92.6:46.26), alkali spreading value (90.9:43.15), yield/plant (78;35.30), head rice recovery (78.9:27.46) and volume expansion ratio (69.1:37.3). In this study the genotypes WGL 1143, WGL 1150, WGL 1149, Tellahamsa in cluster II and WGL 1062 in cluster IV and WGL 915 in cluster VIII were widely divergent and crosses may be effected among the genotypes of the clusters to get more heterosis and subsequently better recombinants in segregating generations.

Reinforced evidence on partial compatibility between Pinus sylvestris and Pinus mugo and on maternal inheritance of chloroplast DNA in the Pinus mugo × Pinus sylvestris cross

The crossability relationship between Scots pine (Pinus sylvestris L.) and mountain dwarf pine (Pinus mugo Turra) was tested under field conditions using an artificial pollination approach. There was partial compatibility between the parental species, as evidenced by the amount of filled seeds in their reciprocal crossings and in control variants from self-pollination, controlled intraspecific outcrossing and open pollination of mother trees. The crossability degree in P. sylvestris × P. mugo was characterised by the index 0.15, and the reciprocal crossing by the index 0.18. Crossability of P. sylvestris and P. mugo with their putative hybrid individuals was much higher; the number of filled seeds was comparable with that of the control variants. The reciprocal crossings of P. sylvestris and P. mugo species were highlighted by the opposite inheritance of their chloroplast DNA (cpDNA). The paternal cpDNA inheritance in P. sylvestris × P. mugo and maternal cpDNA inheritance in P. mugo × P. sylvestris was repeatedly confirmed using the cpDNA trnV-trnH/HinfI marker as well as the newly developed partial cpDNA trnV-trnH/AseI marker. The nature of the latter is described in terms of the nucleotide sequence.

Влияние комплекса микроудобрений на продуктивность клевера лугового в условиях Костромской области

Проведённые исследования показали, что предпосевная обработка семян комплексом АквамиксТ оказывает влияние на повышение зимостойкости растений (опыт 59, контроль 41), устойчивости к неблагоприятным факторам роста, урожайности зелёной массы и способствует улучшению качества полученных семян. При проведении некорневых подкормок комплексом АквамиксТВ наибольшая урожайность зелёной массы (37,8 52,4 т/га) получена в двух вариантах по фону с предпосевной обработкой семян. Это варианты с применением АквамиксТВ в фазу отрастания и совместного его применения в фазы отрастания стеблевания. По контрольному фону урожайность зелёной массы составила 33,7 49,6 т/га. Достоверное увеличение урожайности на 15,9 т/га (при НСР05 15,5 т/га) получено только в одном варианте, при двукратной обработке посевов раствором АквамиксТВ. Наибольшая урожайность семян клевера (1,77 ц/га) обеспечена также в этом варианте по контрольному фону при двукратном опрыскивании АквамиксТВ, применение которого оказывает существенное влияние на качество полученных семян. Наиболее выполненные семена получены в вариантах с применением АквамиксТВ в фазу отрастания и совместном его применении в фазы отрастания и стеблевания по обоим фонам. Особенно отзывчив клевер на подкормки в фазу отрастания, в период наращивания зелёной массы после перезимовки. Второе опрыскивание посевов АквамиксТВ в фазу стеблевания способствует дальнейшему повышению урожайности зелёной массы и семян клевера, а также положительно влияет на посевные качества полученных семян.Conducted researches have shown that presowing seed treatment with the AquamixT complex has an effect on increasing the winter hardiness of plants (experience 59, control 41), resistance to unfavorable growth factors, herbage productivity and contributes to improving the quality of seeds obtained. When carrying out topdressing with the AquamixTV complex the highest yield of herbage (37.8 52.4 t/ha) was obtained in two variants according to the background with presowing seed treatment. These are the variants with the use of AquamixTV in the aftergrowing phase and its combined use in the aftergrowing and stooling stages. According to the control background the yield of herbage was 33.7 49.6 t/ha. A true increase in yield by 15.9 t/ha (with НСР05 15.5 t/ha) was obtained only in one variant with a double treatment of crops with AquamixTV solution. The highest yield of clover seeds (1.77 c/ha) was also ensured in this variant by the control background with double spraying of AquamixTV the use of which has a significant effect on the quality of the seeds obtained. The most filled seeds were obtained in the variants using AquamixTV in the aftergrowing phase and its combined use in the aftergrowing and stoolingstages for both backgrounds. Clover is especially responsive to top dressing in the growing phase during the period of growing herbage after overwintering. The second spraying of AquamixTV crops in the stoolingstage contributes to a further increase in the yield of herbage and clover seeds and also positively affects the sowing qualities of the seeds obtained.

PENGARUH DOLOMIT DAN PUPUK P TERHADAP PERTUMBUHAN DAN PRODUKSI KACANG TANAH (Arachis hypogaea L.) SEBAGAI TANAMAN SELA DIANTARA KELAPA SAWIT DI LAHAN GAMBUT

The research aims to study the interaction of dolomite dose and P fertilizer application on growth and yield of peanut plants as intercropped between palm oil on peatland. The study was conducted in the agriculture experimental station Faculty of Agriculture, University of Riau, Rimbo Panjang village, Kampar District, from December 2015 to April 2016. The research utilizes a Randomized Complete Block Design (RCBD), which consists of two factors. The first factor is dolomite consists of 3 levels (0, 500 and 1000 kg/ha) and second factor P fertilizer consists of 4 levels (0, 23, 46 and 69 kg P2O5/ha), each combination has 4 replication. The parameters observed were plant height, number of primary branches, flowering age, harvesting age, number of pods, number of seeds per pods, the weight of dry seeds and filled seeds/m2, percentage of filled seeds, the weight of 100 seeds. The data of each parameter were analyzed with analysis of variance (ANOVA) followed by Duncan's New Multiple Range Test (DNMRT) at 5% level. The results showed that the increase of weight of dry seeds and filled seeds /m2were significant at the application of 69 kg P2O5/hafollowed by 500 kg dolomite/ha and percentage of filled seeds at the application of 69 kg P2O5/hafollowed by 1000 kg dolomite/ha compared to without P fertilizer and dolomite, whereas in plant height, number of primary branches, flowering age, harvesting age, number of pods, number of seeds per pods and weight 100 seeds were not significant each combination of treatments.

Multivariate Discriminant Analysis of Single Seed Near Infrared Spectra for Sorting Dead-Filled and Viable Seeds of Three Pine Species: Does One Model Fit All Species?

Seed lots of pine species are composed of viable, dead-filled and empty seeds, and the success of complete sorting of dead-filled seeds using the conventional method (Incubation, Drying and Separation in water) is difficult to achieve; leaving a considerable scope for upgrading the sorting efficiency. The objective of this study was to evaluate the prospect of sorting viable and dead-filled seeds of pine species using Near Infrared (NIR) spectroscopy. To demonstrate this, dead-filled and viable seeds of Mason’s pine, slash pine and loblolly pine were incubated in moist medium for three days, dried for six hours and scanned by XDS Rapid Content Analyzer from 780–2500 nm. Orthogonal Projection to Latent Structure-Discriminant Analysis was used to develop discriminant models for each species separately and for all species combined. The results showed that the sensitivity (the model’s ability to correctly classify members of a given class) and the specificity (the model’s ability to reject non-members of a given class) were 100% for each species model and 98%–99% for combined species model. The overall classification accuracy was 100% and 99% for individual species and combined species models, respectively. The absorption band in the 1870–1950 nm with a major peak at 1930 nm, which is related to water, was responsible for discrimination as dead-filled seeds dried quicker than viable seeds during the drying process. Our study is the first attempt to simultaneously discriminate dead-filled and viable seeds of pines by NIR spectroscopy. The results demonstrates that a global calibration model of seed lots of several pine species can be equally effective as the individual species model to discriminate viable and dead-filled seeds by NIR spectroscopy, thereby ensuring precision sowing (also known as single seed sowing) in nurseries.

Physical quality of seeds of Moquiniastrum polymorphum

This study aimed to analyze the physical properties of the seeds of Moquiniastrum polymorphum when processed by mini-SAS, X-ray and seed blower systems. The seeds were purchased from Seeds Caiçara, located in Penápolis-SP. After purchase, the seed lot was characterized by standard tests. In the X-ray test the seeds were classified according to their internal morphology as filled, unfilled or malformed. The seed blower was set at six opening settings, resulting in light and heavy fractions. The evaluations were performed by weighing the seeds that remained in the blower (heavy fraction) and by the amount of filled seeds indicated by the X-ray test. The germination tests were composed of four replicates of 50 seeds. The mini-SAS was used for external evaluation. It was concluded that the combined use of the seed blower and the X-ray test was efficient for the evaluation and determination of the physical quality of the seeds of M. polymorphum. The seed blower at opening settings 5 resulted in the best lot quality. The external parameters were not able to qualitatively evaluate the seeds of M. polymorphum.