The high-affinity K＋/K＋ uptake permease/K＋ transporter (HAK/KUP/KT) family members play important roles in the absorption and transport of potassium (K), regulations of plant growth and development, modulation/acquisition of salt tolerance, and osmotic potential regulation/control. However, this gene family has not been thoroughly studied in Brassica napus. In this study, forty-five BnHAK genes (BnHAK1-BnHAK45) were identified in the B. napus reference genome, and bioinformatic methods were used to resolve the gene structures, evolutionary analysis, expression patterns and chromosome position in different tissues of rape. The results showed that the members of the HAK/KUP/KT gene family were unevenly distributed on the chromosomes, with the most of them located on chromosome A01 which had five BnHAK genes. Phylogenetic analysis of HAK/KUP/KT proteins from multiple species showed that they could be divided into two groups. Among them, Arabidopsis, B. oleracea, B. rapa and B. napus had stronger gene conservation and closer genetic relationships. Although the expression patterns of the HAK/KUP/KT genes were different, in general, they exhibited highest and lowest expression levels in the roots and siliques, respectively, and this showed that there was a functional division of different HAK/KUP/KT gene family members. The expression levels of BnHAK4 and BnHAK9 were highest in the leaves, whilst the expression levels of BnHAK11, BnHAK18, and BnHAK23 were highest in the roots, and BnHAK7 and BnHAK17 were mostly expressed in the flowers, which indicated that the expression of this gene family had tissue specificity. This study provides a reference for further revealing the functional mechanism of HAK/KUP/KT gene family in B. napus.
In order to increase the 1 000-grain mass and yield of film-mulched spring wheat in Hetao irrigation area, we monitored the effects of different supplementary irrigation amounts of 90, 70 and 50 mm water during the heading stage, respectively, on soil moisture and growth of film-mulched spring wheat, taking the conventional irrigation as the control. The results showed that the soil moisture content of film-mulched spring wheat increased at the flowering stage, filling stage and maturity stage by different supplementary irrigation amounts during the heading stage; and the higher the supplementary irrigation amounts were, the higher the soil moisture content and soil moisture evapotranspiration strength, the later the maturity of spring wheat, the less the number of sterile spikelets, and the higher the 1 000-grain mass and grain yields were. The smaller the supple-mentary irrigation amounts were, the higher the yield increase intensity was, but the different supplementary irrigation amounts during the heading stage had no significant effect on the economic coefficient, soil water use efficiency and soil water production efficiency of film-mulched spring wheat. In conclusion, the water quantity of irrigation 50-70 mm should be supplemented in the Hetao irrigation area during the heading stage, which can effectively increase the 1 000-grain mass and yield of film-mulched spring wheat.
In order to expand the germplasm resource bank of cotton after rape cultivation in the Yangtze River Basin, screen out excellent germplasm suitable for hybrid parents, and improve the efficiency of cotton breeding, 11 main agronomic traits of 72 upland cotton materials introduced were analyzed with the methods of variability, correlation analysis, principal component analysis and clustering analysis by statistical software SAS V8. The results showed that, the 72 Gossypium hirsutum germplasm resources had rich genetic diversity, and the variation coefficients of characters among 72 materials ranged from 1.15% to 30.31%. The variation coefficient of boll number per plant was the largest, was 30.31%. The correlation analysis showed that the growth period was significantly and positively correlated with plant type traits. The plant height was extremely significantly and positively correlated with the boll mass. The number of fruit branches per plant was extremely significantly and positively correlated with the boll number per plant, and significantly and negatively correlated with the boll mass. The lint percentage and boll mass were significantly and negatively correlated with some quality traits. The principal component analysis showed that the cumulative contribution rate of the first four principal components was 73.98%, which including most information of 11 traits. Clustering analysis showed that the 72 cotton materials were classified into six groups. Group Ⅰ belonged to high-quality materials, and group Ⅱ belonged to high-yield materials. Group Ⅴ belonged to high-yield and high-quality materials, which could be used in breeding. Two high-quality cotton materials and six high-yield cotton materials were screened out with the method of comprehensive evaluation, which would be used to cultivate new materials with combination of yield and quality traits.
In order to reduce the adverse effects of soil desiccation on apple production and provide scientific support for apple cultivation in Weibei dry plateau, taking apple orchard with vigorous stock dense-planting in full bearing age as a control, the soil moisture contents of dwarfing stock and semi-dwarfing stock dense-planting orchards with same tree age and same fruit yields were adjusted to the same level in the 0-300 cm soil layer before germination stage, and the soil moisture contents in different soil layers in different orchards were monitored regularly. The result showed that the soil moisture content in the 0-300 cm soil layer in the dwarfing stock dense-planting orchard was higher than that in the semi-dwarfing stock dense-planting orchard, and that of in the semi-dwarfing stock dense-planting orchard was higher than that in the vigorous stock dense-planting orchard, and the gap between different orchards gradually increased from spring to autumn. The soil evapotranspiration of the dwarfing stock dense-planting, semi-dwarfing stock dense-planting and vigorous stock dense-planting orchards were 4.51, 46.37 and 92.70 mm higher than that of the precipitation in the same period during the monitoring period (from March to November in 2016), respectively; as such, they were －18.06, 22.35 and 65.34 mm higher during the growth period of apple trees (from April to October in 2016), respectively, which indicated that the vigorous stock dense-planting pattern increased the soil desiccation. The water use efficiency of dwarfing stock dense-planting and semi-dwarfing stock dense-planting orchards increased by 14.98% and 9.58%, respectively. In a sum, dwarfing stock dense-planting and semi-dwarfing stock dense-planting patterns could not only slow down the soil desiccation, but also could increase soil water use efficiency and production value, so dwarfing and semi-dwarfing stock dense-planting patterns should be popularized in Weibei dry plateau.
Heat stress has increasingly become a global problem affecting agriculture including cotton production which is a critical fiber and oil crop. The purpose of this study was to evaluate six transgenic insect-resistant and herbicide-tolerant cotton germplasms (HNZ 1063, HNZ 1068, HNZ 1073, HNZ 1081, HNZ 1088 and HNZ 1091) and the conventional cultivar Zhongmiansuo 49 (ZMS 49) based on the evaluation and screening of membrane thermostability, pollen viability and chlorophyll stability of field plants as an initial study. A follow up study was conducted using four-week-old seedlings treated at 42 ℃ (light)/24 ℃ (dark) for one week to further evaluate heat tolerance by measuring and analyzing photosynthetic rate, chlorophyll content, antioxidant enzyme activity and growth parameters. The results showed that three germplasms, HNZ 1091, HNZ 1068 and ZMS 49, were more heat-tolerant, while two, HNZ 1081 and 1073, were less tolerant. It can thus be concluded that there are differences in heat tolerance among different transgenic lines inserting the same gene.
Taking the seeds of six early rice cultivars ‘Zhuliangyou 06’, ‘Zhuliangyou 101’, ‘Zhongzao 39’, ‘Jinzao 47’, ‘Zhongjiazao 17’ and ‘Yongxian 15’ as materials, the seed vigor of these early cultivars was determinated by the standard germination test, low temperature germination test (12 ℃, 15 ℃ and 18 ℃) and field emergence test. The results showed that the germination percentages at 18 ℃ after 4-5 days and 15 ℃ after 5-7 days had significantly positive relationship to the field emergence (FE). Especially, the correlation coefficient between germination percentage at 18 ℃ after 4 days and FE reached 0.932, revealing a fast and accurate method for measuring the seed vigor at a low temperature. The endogenous ABA content of seed at 18 ℃ after 4 days were negatively related to the germination percentages and FE. The real-time fluorescence quantitative polymerase chain reaction analysis showed the expression levels of ABA-synthesis related genes in high-vigor seeds were significantly lower than those in the low-vigor seeds. However, the most genes involved in ABA-catabolism and signal transduction related genes were highly expressed in the high-vigor seeds. Different responses in ABA metabolism and chilling signal transduction to low temperature stress might explain the seed vigor differences in the 12 early rice seed samples. The present study further reveals the internal mechanism of low temperature stress regulating seed vigor of early rice, which could provide a new theoretical basis for testing seed vigor of early rice with low temperature germination test.
In order to improve the economic benefits of the apple orchard in Weibei dry plateau, taking the apple orchard with vigorous stock dense planting at the full bearing age as a control, the bearing fruit number of dwarfing stock dense planting and semi-dwarfing stock dense planting orchards were kept to the same with the vigorous stock dense planting orchard, and the tree growth status in different dense planting orchards with different stock-scion combinations was monitored. The results showed that the leaf area indexes of the dwarfing stock dense planting and semi-dwarfing stock dense planting orchards were 30.47% and 23.98% lower, and the leaf transpiration rates were 7.56% and 5.84% lower, but the leaf photosynthesis rates were 17.36% and 9.88% higher than that of the vigorous stock dense planting orchard, respectively. The tree growth in the dwarfing stock dense planting and semi-dwarfing stock dense planting orchards was smaller, but the fruit yields were basically consistent with that in the vigorous stock dense planting orchard. The fruit output value of the dwarfing stock dense planting and semi-dwarfing stock dense planting orchards increased by 8.58% and 7.43%, compared with that of the vigorous stock dense planting orchard, respectively. The above results indicate that the dwarfing stock dense planting and semi-dwarfing stock dense planting patterns can increase the production value of apple orchard, so the two dense planting patterns should be popularized in Weibei dry plateau.
This study aimed to explore the influence of different monochromatic lights on the growth and antioxidant enzyme activity of the mycelia of fungus Sanghuangporus sanghuang. We used a light emitting diode (LED)-based light source as a monochromatic light source, including the blue light (455-490 nm), green light (515-540 nm), yellow light (580-600 nm) and red light (610-710 nm), and taking the white light (390-710 nm) as a control. The growth status, morphological characteristics, malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD) and catalase (CAT) of this strain were studied under the irradiation of different monochromatic lights. The results indicated that, compared with those under the white light, the colony diameter of S. sanghuang increased significantly and the mycelia were denser under the red light, and the fungal growth was inhibited under the blue light and green light, but there was a minimal impact on the fungal growth under the yellow light. The SOD activity of mycelium increased significantly after 9 d of irradiation under the blue light, green light and yellow light, respectively (P＜0.05), while it decreased significantly after 3 d of irradiation under the red light. The CAT activity of mycelium increased under the four monochromatic lights. On the 11th day, the CAT activity increased significantly (P＜0.05), reaching to (31.82±1.60) U/(g?min) under the yellow light. The highest MDA content was observed under the blue light on the 9th day, reaching to (1.07±0.03) mmol/g, which was around 1.16 times under the white light; however, no significant change in the MDA content was observed under the other monochromatic lights. In summary, different monochromatic lights impose different influences on the growth and antioxidant enzyme activity of S. sanghuang, and the red light is more favorable for the growth than the other tested lights.
In order to investigate the effects of establishment of photovoltaic (PV) panels on field illumination conditions and sweet potato growth in an agro-photovoltaic integrating system, we used wooden boards to simulate the PV panel construction. The simulated PV assembly had a set of standard parameters, which were an average height of 1.6 m, a slope of 22°, a width of 3 m and a length of 9 m. A two-year field experiment was carried out, and three sweet potato cultivars of “Xinxiang” (Xx) , “Zheshu 13” (ZS 13) and “Zheshu 77” (ZS 77) were planted under the PV panel shading and CK (without PV panels) treatments. The results showed that under the sunny weather condition, the illumination intensity was 80-400 μmol/(m2?s), which was higher than the light compensation point of the tested cultivars and slightly lower than the light saturation point of Xx and ZS 13. The variation of field light intensity in cloudy days of summer and autumn was similar to that in the sunny days. The light intensity of observation points under the PV panel shading treatment in rainy days was only slightly higher than the light compensation point of the tested cultivars. At the same light intensity, the net photosynthetic rate and stomatal conductance of sweet potato leaves under the shading treatment decreased significantly, and the intercellular CO2 concentration increased significantly. After the PV panel shading treatment, the maximum leaf area per plant decreased significantly, and the leaf area of Xx, ZS 13 and ZS 77 decreased by 18.94%, 45.54% and 56.26%, respectively. The leaf mass of per area for the three cultivars also decreased significantly. The dry matter accumulation trend of the three cultivars after shading treatment was the same as that of the CK, but the total amount decreased significantly. Compared with the CK, the yield of sweet potato per unit area decreased by 39.25%, 33.70% and 23.60% for Xx, ZS13 and ZS 77, respectively, but the total yield of Xx was still the highest under the shading treatment. In summary, the agro-photovoltaic integrating system formed by the construction of photovoltaic panels in the farmland has some adverse effects on the field light intensity and sweet potato growth, but the economic benefits per unit area are greatly increased. Thus, the crop yield can be increased by increasing density of sweet potato seedlings and reasonable fertilizer, and the agro-photovoltaic integrating system has a good prospect of popularization.
To clarify the stem lodging resistance characteristics and common characteristics of high-yielding indica hybrid rice cultivars with good quality under precision direct seeding in different ecological areas, and furthermore, to investigate the correlation analysis between the lodging index, breaking resistance and panicle traits, main culm physical characteristics, this study selected two rice fields in the western Sichuan Plain and the middle Sichuan hills as the research objects, and 15 different indica hybrid rice cultivars were used as materials in the two ecological zones, and mechanized precise hill-seeding (the following referred to precision direct seeding) were artificially simulated. The results showed that by a cluster analysis based on average grain yield of each cultivar in the two zones, the 15 tested cultivars could be classified into three levels: high-yielding, medium-yielding, and low-yielding. In the different ecological areas, compared with medium-yielding and low-yielding cultivars, the high-yielding cultivars had high stem plumpness status, good mechanical strength and obvious lodging resistance advantages. Its dry mass of single ear was 4.56-5.35 g; the number of primary branches was 14.55-15.17; the number of secondary branches was 49.58-60.67; N1-N3 (the first to the third internode from the base) internode length was 25.70-26.67 cm; the gravity center height was 53.97-59.37 cm; the average internode thickness of the base N1-N3 was 5.75-6.26 mm; the internode culm wall thickness was 1.09-1.20 mm; the average stem mass was 0.20-0.24 g, and the sheath dry mass was 0.22-0.23 g. As a result of their improved spike composition and stalk physical characteristics, the comprehensive breaking resistance of the culm of high-yielding cultivars was improved evidently, and the lodging index reduced as well. Besides, the correlation analysis also showed that the breaking resistance of the 1st, 2nd, 3rd internodes had significant or extremely significant positive correlations with the number of first and second branches, single panicle mass, grain density, grain yield, bending moment, stem length, gravity center height, ratio of gravity center height to plant height, internode diameter, culm wall thickness, culm type index, flat rate, dry mass of culm, dry mass of leaf sheath, and dry mass of unit internode, especially with the highest dry mass of unit internode (r=0.855-0.937), while it showed a significant or very significant negative correlation with the internode length . It shows that reasonable control of the proportion of basal internodes and emphasis on improving the culm wall thickness and strengthening plumpness status of culm are reliable ways to harmonize the high yield and high lodging resistance of the high-quality indica hybrid rice cultivars.
The wild-type (WT) barley ZJU3 and wax-deficient mutant P1 were used as experimental materials. Using the solution culture methods, when the seedlings growing to two leaves, drought stress was simulated by different concentrations of PEG (macrogol)-6000 to compare the physiological and biochemical indexes of the mutant and wild type seedlings. At the same time, the expressions of 10 waxy-related genes were detected by real-time polymerase chain reaction (PCR). The results showed that under drought stress, the activities of superoxide dismutase (SOD) and peroxidase (POD) increased first and then decreased, and the proline (Pro) content increased continuously, and the malondialdehyde (MDA) content increased, indicating that the loss of barley wax powder would reduce its drought resistance. Among the 10 waxy genes selected, P1 had six down-regulated genes with respect to ZJU3, and three genes were up-regulated. Only one gene expression was not significantly different. The study preliminarily reveals the characteristics of the mutant and its advantages in drought resistance.
