The Amino Acid-Mediated TOR Pathway Regulates Reproductive Potential and Population Growth in Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae)

The predatory mirid bug, Cyrtorhinus lividipennis Reuter, feeds on brown planthopper (BPH) eggs that are deposited on rice and gramineous plants surrounding rice fields. The development and reproduction of C. lividipennis are inhibited by feeding on BPH eggs from gramineous species, and the underlining regulatory mechanism for this phenomenon is unclear. In the present study, HPLC-MS/MS analysis revealed that the concentrations of six amino acids (AAs:Ala, Arg, Ser, Lys, Thr, and Pro) were significantly higher in rice than in five gramineous species. When C. lividipennis fed on gramineous plants with BPH eggs, expression of several genes in the target of rapamycin (TOR) pathway (Rheb, TOR, and S6K) were significantly lower than that in the insects fed on rice plants with BPH eggs. Treatment of C. lividipennis females with rapamycin, dsRheb, dsTOR, or dsS6K caused a decrease in Rheb, TOR, and S6K expression, and these effects were partially rescued by the juvenile hormone (JH) analog, methoprene. Dietary dsTOR treatment significantly influenced a number of physiological parameters and resulted in impaired predatory capacity, fecundity, and population growth. This study indicates that these six AAs play an important role in the mediated-TOR pathway, which in turn regulates vitellogenin (Vg) synthesis, reproduction, and population growth in C. lividipennis.

Short-season varieties of red clover on the drainage lands of the Non-Chernozem region

Представлены полученные в отделе кормопроизводства ФГБНУ ВНИИМЗ трехлетние данные по продуктивности травосмесей на основе клевера лугового, люцерны изменчивой и злаковых трав на осушаемой почве Нечерноземья. В опыте, заложенном в 2012 году, представлены сравнительные данные роста, развития и урожайности зелёной массы разноспелых травосмесей за период 2012 2015 годов. Исследования проводились на институтском полигоне в Тверской области. Возделывание многолетних трав в смесях на кормовые цели обеспечивает их эффективное использование при затратах на посев один раз в 5 и более лет, сокращённых затратах на уборку урожая и минеральные подкормки в связи с использованием в смесях двух бобовых культур. Рекомендуемый разноспелый сортовой состав клевера лугового и расширенный видовой состав злаковых компонентов позволяет удлинить время их скашивания. Введение в сельскохозяйственное производство многокомпонентных травосмесей обеспечивает максимальную урожайность зелёной массы за два укоса (до 40 т/га) и получение полноценного зелёного корма для крупного рогатого скота в течение июняавгуста, что особенно важно в настоящее время. Отмечено, что возделывание в смесях бобовых трав разных лет жизни клевера лугового и люцерны изменчивой со злаковыми травами способствует стабилизации и продлению продуктивности травосмесей при удешевлении производства кормов и сохранении плодородия почвы. В ходе проведения опыта определены и рекомендованы наиболее приспособленные к условиям гумидной зоны бобовозлаковые трёхкомпонентные травосмеси, отличающиеся высокопродуктивным долголетием. This paper presents the data on ecosystem productivity cultivated on the drainage lands of the NonChernozem region in 2012 2015. Mixtures were composed of red clover, bastard alfalfa and gramineous. The experiment taken place in the Tver region dealt with plant height, growth and green mass productivity. Introduction of two legume crops into grass mixtures was effective and reduced seeding, harvesting and fertilizer costs. Combination of clover of various maturation times with different gramineous species extended cutting time of grass mixtures. Multicomponent mixtures produced up to 40 t ha1 of green mass for 2 cuts and provided cattle with green forage in JuneAugust. Growing crops of different maturation times as mixtures optimized and increased ecosystem productivities as well as reduced production costs and maintained soil fertility. The experiment determined threecomponent legumegramineous mixtures that had the best adaptability to the humid zone and productive longevity.

Recovery and germination of seeds after passage through the gut of Kazakh sheep on the north slope of the Tianshan Mountains

Endozoochorous dispersal of seeds by livestock has long attracted the attention of grassland scientists. However, little is known about seed dispersal after ingestion by Kazakh sheep on dry grasslands in the Tianshan Mountains. The objective of this experiment was to learn more about the recovery and germinability of seeds from 17 plant species after either actual or simulated ingestion (i.e. insertion through a rumen fistula) by Kazakh sheep. The passage time of seeds through the sheep gut ranged from 12 to 96 h. More than 80% of all recovered seeds were defecated 24–48 h after ingestion. The mean retention time of seeds in the gut ranged from 27.3 to 42.2 h. Seed recovery percentage ranged between 12.6 and 17.6% for leguminous species and between 0.8 and 3.2% for gramineous species. Seed recovery percentage was positively correlated with seed mass, but negatively correlated with seed shape. The germination percentages of the gramineous species were greater in the non-ingested treatment (66–98%) than in the simulated ingestion treatment (3–10%). In contrast, for leguminous species, seed germination percentages were greater in the simulated ingestion treatment (23–70%) than in the non-ingested one (5–12%). Seed germination percentage after simulated ingestion was positively correlated with seed mass, but negatively correlated with seed shape. In conclusion, leguminous seeds were more likely than gramineous ones to pass through the gut of Kazakh sheep and then germinate. Free-ranging Kazakh sheep can contribute to the spread of plant species, especially leguminous species, in the Tianshan Mountains.

Leguminous species sequester more carbon than gramineous species in cultivated grasslands of a semi-arid area

The establishment of grasslands on abandoned cropland has been proposed as an effective method to mitigate climate change. In this study, five cultivated grasslands (three leguminous species and two gramineous species), one abandoned cropland, and one natural grassland were studied to examine how soil organic carbon (SOC) sequestration rate and sequestration efficiency change in a semi-arid area in China. Our results showed that leguminous grasslands had greater total biomass (above- and belowground biomass), SOC storage, SOC sequestration rate, and efficiency than gramineous grasslands, abandoned cropland, and natural grassland during the experimental period. The largest soil carbon (C) accumulation in leguminous grassland was mainly attributed to the capacity to incorporate C and the higher biomass production. Leguminous grasslands accumulated more SOC than gramineous grasslands by 0.64 Mg C ha−1 yr−1. The average SOC sequestration efficiency in leguminous grassland (1.00) was about 2 times greater than gramineous grassland (0.34). The results indicate that cultivated leguminous grassland sequestered more SOC with higher SOC sequestration efficiency than cultivated gramineous grassland in arid and semi-arid areas. Our results provide a reference for ecological management in arid and semi-arid areas.

Cultivated grasslands present a higher soil organic carbon sequestration efficiency under leguminous than under gramineous species

The establishment of grassland on abandoned cropland has been proposed as an effective method of mitigating climate change by increasing soil organic carbon (SOC) storage. In this study, five cultivated grasslands were established (three leguminous species – Coronilla varia, Onobrychis viciaefolia, Medicago sativa, and two gramineous species – Poa annua, Agropyron cristatum), one uncultivated, one natural grassland to examine how the SOC storage, sequestration rate and sequestration efficiency to change for 5 years restoration in semi-arid area. Our results showed that the cultivated leguminous grasslands had greater total biomass, SOC storage, SOC sequestration rate and efficiency than gramineous grasslands. The greater soil carbon (C) accumulation in leguminous grassland was mainly attributed to higher biomass production. Leguminous grasslands accumulated more SOC than gramineous grasslands by 0.64 Mg C ha−1 yr−1. The average SOC sequestration efficiency in leguminous grassland (1.00) was about 2 times greater than gramineous grassland (0.34). The results indicate that cultivated leguminous grasslands sequestered more SOC with higher SOC sequestration efficiency than cultivated gramineous grasslands in arid and semi-arid areas.