Agronomic traits at the seedling stage,yield, and fiber quality in two cotton (Gossypium hirsutum L.) cultivars in response to phosphorus deficiency

ABSTRACT

Cotton is critical for phosphorus demands and very sensitive for its deficiency. However, identifying the effect of low-phosphorus tolerance on cotton growth, yield, and fiber quality by reducing phosphorus consumption. This may help to develop phosphorus-tolerant high-yielding cotton cultivars. In a two-year repeated (2015 and 2016) hydroponic experiment (using 0.01 and 1 mM KH₂PO₄), two cotton cultivars with phosphorus sensitivity (Lu 54; a low-phosphorus sensitive and Yuzaomian 9110; a low-phosphorus tolerant) were screened on the base of agronomic traits and physiological indices through correlation analysis, cluster analysis and principal component analysis from 16 cotton cultivars. Low phosphorus nutrition reduced the plant height, leaf number, leaf area, phosphorus accumulation and biomass in various organs of seedlings. The deficiency negatively affected the morphogenesis of seedlings, as well as yield and fiber quality. Further, these screened cultivars were tested in a pot experiment with 0, 50, 100, 150, 200 kg P₂O₅ ha^?1 during 2016 and 2017. It was found to have a significant (P< 0.05) difference in boll number, lint yield, fiber strength, and micronaire at the harvest. Furthermore, after collectively analyzed the characteristics of Lu 54 and Yuzaomian 9110, there were six key indices that could improve the low phosphorus tolerance of cotton cultivars. These were root phosphorus accumulation, stem phosphorus accumulation percentage, leaf and total biomass of seedlings, seed cotton weight per boll and fiber length.     

Analysis of the variations in dry matter yield and resource use efficiency of maize under different rates of nitrogen,phosphorous and water supply

Abstract

Increasing resources use efficiency in intensive cultivation systems of maize (Zea mays L.) can play an important role in increasing the production and sustainability of agricultural systems. The objectives of the present study were to evaluate DM yield and the efficiency of inputs uses under different levels of water, nitrogen (N) and phosphorus (P) in maize. Therefore, three levels of irrigation including 80 (ETc₈₀), 100 (ETc₁₀₀) and 120% (ETc₁₂₀) of crop evapotranspiration were considered as the main plots, and the factorial combination of three levels of zero (N₀), 200 (N₂₀₀) and 400 (N₄₀₀) kg N ha^?1 with three levels of zero (P₀), 100(P₁₀₀) and 200 (P₂₀₀) kg P ha^?1 was considered as the sub plots. The results showed that increasing the consumption of water and P was led to the reduction of N and P utilization efficiency, while RUE increased. WUE was also increased in response to application of N and P, but decreased when ET_C increased. DM yield under ETc₈₀ treatment reduced by 11 and 12%, respectively, compared to ETc₁₀₀ and ETc₁₂₀ which was due to reduction of cumulative absorbed radiation (R_abs(cum)) and RUE. Under these conditions, changes of stomatal conductance (gs) had little effect on DM yield. It was also found that N limitation caused 11 and 20% reduction in DM yield compared to N₂₀₀ and N₄₀₀, respectively. This yield reduction was mainly the result of decrease in RUE. By decreasing R_abs(cum), P deficiency also reduced DM yield by 5 and 9%, respectively, relative to P₁₀₀ and P₂₀₀ treatments.     

Zu Prekler’s „rationellem Baldwirth“

Ohne Zusammenfassung f. f?chf. Dberforftmeifter. f. bahr. Regierungs- und Forftrath von Mürzburg. f. preuk. Dberforftmeifter aus Breslau. f. f?chf. Dberforftmeifter. f. bahr. Regierungs- und Forftrath von Augsburg. f. bahr. Regierungs- und Forftrath aus Regensburg. Dberj?germeifter von Braunfchweig. f. bahr. Regierungs- und Forftrath aus München. f. f?chf. Dberf?rfter. f. f?chf. Dberforftmeifter. f. f?chf. Dberforftrath. herz. braunfchweig. Forftmeifter von Blanfenburg. Direftor der fürftlich Cfterhazh’fchen Herrfchaft Spoly Parsto. fürftl. fondershauf. Dberfortmeifter. f. bahr. Redierf?rfter don Schmarzenbach. f. preuk. Dberf?rfter. f. f. Forftrath aus Brekburg. f. preuk. Dberf?rfter von Altruppin. f. hann?v. Forftmeifter von Rienburg. Forftmeifter in preuk. Schleften. f. preuk. Dberforftmeifter von Berlin. herz. aftenburg. Dberfortmeifter. f. preuk. Dberf?rfter. f. f?chf. Dberf?rfter. f. ruff. Forftfomiff?r aus Marfchau. f. preuk. Forftinfpeftor. f. f?chf. Forftinfpeftor. grokh. meimar. Forftinfpeftor von Martfuhl. f. mürttb. Dberf?rfter und Brofeffor aus Hohenheim. f. hannov. Forftmeifter aus Hammeln. Dberforftmeifter aus Sotha. herz. altenburg. Dberf?rfter aus Hummelshain. herz. altenburg. Revierf?rfter aus Milchwig. herz. altenburg. geheimer Finanzrath und Dberforftmeifter. herz. altenb. Dberforftmeifter aus Hummelshain. grokh. f?chf. geheimer Dberforftrath aus Qifenach. herz. naffau. Dberforftrath aus Miesbaden. grokh. heff. Dberforftfefret?r aus Darmftadt. f. f?chf. Dberforftmeifter.     

Recent research in Roumania on blackleg and bacterial soft rot of potato

Summary Potato blackleg has been known in Roumania for more than 35 years, but has become increasingly serious in recent times. The disease is mainly restricted to the central and northern regions, which have a rainy climate with moderate temperatures. In areas where the climate is warm and dry, the disease appears only sporadically, and even then, its development is slow. The principal means of transmission of the disease from one year to another is by infected tubers, the causal organ does not persist long in unsterile soil. Potato blackleg and soft rot in Roumania is produced not only byE. atroseptica, for an important part in the disease complex especially in storage is played by the bacteriaE. carotovora andE. aroideae. E. atroseptica, owing to its special preference for the stems of the plants, is considered as the principal pathogenic agent, while the other two organisms occur more frequently in the tubers. It is considered that the divergent characteristics of the organisms justify keeping them as two or even three separate species and not as variants of a single species.

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Zusammenfassung In den Jahren 1961 bis 1963 wurden am Biologischen Institut Traian Savulescu in Bukarest, Rum?nien, Untersuchungen durchgeführt über die Verbreitung der Schwarzbeinigkeit bei Kartoffeln im Zusammenhang mit den klimatischen Verh?ltnissen in Rum?nien, mit den Bedingungen, unter welchen die Infektion und die übertragung der Krankheit stattfindet, mit der Etiologie der Krankheit in Rum?nien und mit gewissen charakteristischen Eigenschaften der Krankheitserreger. Kartoffel-Schwarzbeinigkeit ist in Rum?nien schon seit mehr als 35 Jahren bekannt, aber in letzter Zeit hat sie ernstere Formen angenommen. Die Infektion im Feld schwankt von 1–15% und nimmt w?hrend der Lagerung zu. Die Krankheit beschr?nkt sich haupts?chlich auf die zentralen und n?rdlichen Regionen des Landes, wo ein regnerisches Klima mit m?ssigen Temperaturen vorherrscht. Im Süden, wo Frühling und Sommer in der Regel heiss und trocken sind, scheint sie eigentlich nicht vorzukommen, selbst nicht in Feldern, die mit Knollen aus befallenen Gebieten bepflanzt sind. Es ist festgestellt worden, dass die übertragung dieser Krankheit von einem Jahr auf das andere haupts?chlich durch befallene Knollen geschieht. Der Boden bildet nur in dem Mass eine Infektionsquelle, als er nicht verfaulte Reste von kranken Pflanzen enth?lt. Es wurde dargelegt, dass die Bakterien in nicht sterilem Boden ihre überlebensf?higkeit rasch verlieren (Tabelle 1). Was die Etiologie der Schwarzbeinigkeit betrifft, wurde herausgefunden, dass nebenErwinia atroseptica—in Rum?nien bis jetzt als die einzige Ursache dieser Krankheit angenommen — auchE. carotovora undE. aroideae, speziell w?hrend der Lagerung, eine wichtige Rolle im Krankheitskomplex spielen. Unsere Beobachtungen und Untersuchungen haben ergeben, dassE. atroseptica der Hauptkrankheitserreger im Feld ist, der besonders die Stengel bef?llt. Die beiden andern Bakterien kommen ebenfalls vor, doch werden sie gew?hnlich auf den Knollen am Lager gefunden, wo sie — unter günstigen Bedingungen — einen viel h?ufigeren Befall erzeugen k?nnen alsE. atroseptica. Es wurde festgestellt, dass sowohl Eigenschaften, wie der Grad der Pathogenit?t an Stengeln und Knollen, Reaktionen auf Zuckern und besonders das Verhalten auf Maltose und auf durchtr?nktes Korn-Pepton-Glukose-Agar-Medium, das Wachstum bei hohen Temperaturen (Tabelle 2) und serologische Reaktionen (Tabelle 3) wie auch toxische und immunologische Wirkungen auf Tiere bei der Unterscheidung der drei Bakterien von Nutzen sind. Es wird darauf hingewiesen, dass die hier berichteten Ergebnisse die Ansicht jener Forscher best?rken und rechtfertigen, die glauben, dass die drei Bakterien als verschiedene Arten betrachtet werden sollten.

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Résumé A l'Institut de Biologie Traian Savulescu à Bucarest. Roumanie, les recherches suivantes ont été effectuées durant la période 1961–1963; l'apparition de la maladie de la jambe noire en relation avec les conditions climatiques en Roumanie, les conditions sous lesquelles ont lieu l'infection et la transmission de la maladie, l'étiologie de la maladie en Roumanie et certains caractères des pathogènes. La jambe noire de la Pomme de terre est connue en Roumanie depuis plus de 35 ans mais est devenue progressivement grave dans les derniers temps. L'infection dans les champs varie de 1 à 15% et augmente pendant la conservation. La maladie est essentiellement limitée aux régions du centre et du nord du pays qui ont un climat pluvieux et des températures modérées. Dans le sud, où le printemps et l'été sont habituellement chauds et secs, la jambe noire semble être réellement absente, même dans les champs plantés avec des tubercules provenant de régions infectées. Il a été établi que la transmission de la maladie d'une année à l'autre a lieu principalement par les tubercules infectés, le sol étant la source d'infection dans la seule mesure où il contient des restes non détruits de plantes malades. Il a été démontré que les bactéries perdent rapidement leur viabilité dans les sols non stériles (Tableau 1). Concernant l'étiologie de la jambe noire, on a trouvé que outreErwinia atroseptica que, jusqu'à présent, on croyait être la seule cause de la maladie en Roumanie,E. carotovora etE. aroideae jouent également un r?le important, spécialement pendant la conservation. Selon nos observations et expériences,E. atroseptica est le principal agent pathogène dans le champ, montrant une préférence marquée pour les tiges, tandis qu'apparaissent aussi les deux autres bactéries qui, toutefois, sont plus communément trouvées sur les tubercules pendant la conservation; à ce moment, sous des conditions favorables, les attaques de ces dernières peuvent être beaucoup plus grandes que celles deE. atroseptica. Les déterminations des comportements suivants se sont révélées pleinement utiles pour différencier les trois bactéries: les degrés d'attaques sur tiges et tubercules, les réactions sur sucres et spécialement leurs réactions sur maltose et sur milieu agar glucose peptone de grains trempés, leur développement à hautes températures (Tpableau 2) et leurs réactions sérologiques (Tpableau 3) aussi bien comme effets toxiques qu'immunologiques sur les animaux. Les résultats rapportés ici prouvent et développent les vues de ces chercheurs qui croient que les trois bactéries seraient à considérer comme espèces séparées.

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Paper read to the Pathology Section of the Second Triennial Conference of the European Association for Potato Research, Italy, September 1963.     

Effect of in vitro exposure to Vibrio vulnificus on hydroelectrolytic transport and structural changes of sea bream (Sparus aurata L.) intestine

The everted gut sac technique has been used to investigate the effect of Vibrio vulnificus on water and electrolyte (Na⁺, K⁺, Cl⁻, HCO₃ ⁻) transport on the intestine of sea bream (Sparus aurata L.). Both the anterior and the posterior intestine were incubated in a medium containing 10⁸ V. vulnificus cells ml⁻¹ at 25°C for 2 h. The presence of V. vulnificus resulted in a significant reduction (P < 0.05) of water absorption in the anterior intestine, while sodium absorption in the anterior (P < 0.01) and posterior (P < 0.05) intestine was elevated. Chloride absorption was increased, but the changed was not significant, while potassium absorption decreased significantly (P < 0.05), but only in the posterior intestine. Incubation the sea bream intestine with V. vulnificus did not affect carbonate secretion in the anterior segment, whereas high secretion was stimulated in the posterior segment (P < 0.01). Histological evaluations demonstrated damage in the anterior intestine of sea bream that was characterized by the detachment of degenerative enterocytes, alterations in the microvilli, and the presence of a heterogenous cell population, indicating inflammation. Based on our results, we conclude that V. vulnificus caused cell damage to the intestine of sea bream and that the anterior intestine is more susceptible than the posterior part of the intestine. Several hypotheses are suggested to explain our observations, such as the presence of higher numbers of villosities in the anterior intestine than in the posterior one and/or the presence of endogenous bacteria in the posterior intestine which may have a protector role.     

Some Limiting Factors in Superintensive Production of Juvenile Pacific White Shrimp,Litopenaeus vannamei,in No‐water‐exchange,Biofloc‐dominated Systems

Superintensive shrimp culture in zero‐exchange, biofloc‐dominated production systems is more biosecure and sustainable than traditional shrimp farming practices. However, successful application of this technology depends upon optimizing dietary formulations, controlling Vibrio outbreaks, and managing accumulative changes in water quality and composition. A 49‐d study investigated the effect of two commercial feeds of differing protein content and an indoor limited‐exchange, biofloc‐dominated culture environment on Litopenaeus vannamei performance and tissue composition, water quality and ionic composition, and Vibrio dynamics. Juveniles (5.3 g) were stocked at 457/m³ into four 40 m³ shallow raceways containing biofloc‐dominated water and fed one of two commercial feeds with differing protein content, 35 or 40%. Shrimp performance, Vibrio populations, and changes in shrimp and culture water composition were monitored. There were no significant differences (P > 0.05) in shrimp performance (survival, weight, growth, specific growth rate, total biomass, yield, feed conversion ratio, and protein efficiency ratio) or proximate composition between feed types. The 40% protein feed resulted in higher culture water nitrate and phosphate concentrations, alkalinity consumption and bicarbonate use, and higher phytoplankton density. The presence of Vibrio, specifically Vibrio parahaemolyticus, reduced shrimp survival. This survival decrease corresponded with increased culture water Vibrio concentrations. Culture water K⁺ and Mg²⁺ increased significantly (P < 0.05), and Sr²⁺, Br^?, and Cl^? decreased significantly (P < 0.05) over time. While Cu²⁺ and Zn²⁺ did increase in shrimp tissue, no heavy metals accumulated to problematic levels in culture water or shrimp tissue. These results demonstrate the importance of monitoring Vibrio populations and ionic composition in limited‐exchange shrimp culture systems.     

Linking the abundance of aspen with soil faunal communities and rates of belowground processes within single stands of mixed aspen–black spruce

The occurrence of aspen (Populus tremuloides Michx.) patches within stands dominated by black spruce (Picea mariana Mill. BSP) has been shown to increase litter decomposition and nutrient cycling rates by improving soil physical and chemical properties. It is well known, however, that these processes are also influenced by the structure of the soil biota, but this factor has received less attention. In this study, relationships between forest floor properties and soil invertebrates were studied along black spruce–trembling aspen gradients in three stands of the eastern boreal forest of Canada. The forest floor layer of 36 plots differing in aspen basal area was sampled and analyzed to determine physical and chemical properties, the rates of decomposition of standard substrates, net N mineralization, as well as microbial basal respiration and metabolic quotient. Soil invertebrates were also collected using funnel-extraction and pitfall trapping methods. Based on redundancy analyses, we found that forest floor properties, the abundance and composition of soil invertebrates, and the rates of belowground processes changed along the spruce–aspen gradient. The increase in aspen basal area was associated with a reduction in forest floor thickness, moisture content and microbial biomass, and with an increase in the concentration of nutrients. It was also accompanied by changes in soil faunal communities, as soil invertebrates were associated with specific soil properties. In general, macroinvertebrates (i.e., Lumbricidae, Formicidae, Carabidae, Staphylinidae and Gastropoda) were related to the nutrient-rich forest floor associated with aspen, whereas microarthropods and Enchytraeidae tended to be negatively related to aspen basal area. According to mixed linear models, decomposition rates of standard substrates and net ammonification significantly increased along the spruce–aspen gradient. Given the functional significance of macroinvertebrates in soils, these results suggest that aspen favours the elaboration of a macrofaunal community, which in turn accelerates the rate of soil processes by having either direct or indirect influence on microbial activity. Moreover, this study shows that the changes in soil processes and in the biodiversity of soil organisms related to the presence of mixed stands can operate only in the immediate surroundings of a given tree species. Therefore, coarse-scale tree species mixing in a forest stand may have a different effect on soil biodiversity and soil processes than fine-scale mixing.