scholarly journals Megalobrama amblycephala grazes preferentially on Hydrilla verticillata but makes more efficient use of Vallisneria denseserrulata: implications for biological control of submerged macrophytes

2019 ◽  
pp. 30 ◽  
Author(s):  
Chunyu Yin ◽  
Zhaoxia Wang ◽  
Yu Zhao ◽  
Yiming Gao ◽  
Wei Zhen ◽  
...  
Keyword(s):  
Submerged Macrophytes ◽  
Hydrilla Verticillata ◽  
Megalobrama Amblycephala ◽  
Food Utilization ◽  
Root Weight ◽  
Fresh Weight ◽  
Blade Width ◽  
Negative Effect ◽  
Maximum Root Length ◽  
Maximum Root

Growth of the meadow-forming macrophyte Vallisneria denseserrulata is often negatively impacted as result of shading by the canopy-forming Hydrilla verticillata. Grazing by the herbivorous cyprinid Megalobrama amblycephala is thought to control H. verticillata. We hypothesized that M. amblycephala would prefer H. verticillata over V. denseserrulata, and that where the latter is grazed, its growth will not be wholly compromised, due in part to the efficiency with which it is metabolized by the grazer. In a pond experiment, macrophytes were planted with monocultures of H. verticillata and V. denseserrulata, and in mixed cultures of the two species, with and without grazing by M. amblycephala. The results showed that in the absence of fish, the growth rate of V. denseserrulata was significantly reduced in the presence of H. verticillata. In the mixture, M. amblycephala had a significant negative effect on the growth of H. verticillata but not on V. denseserrulata. Grazing was associated with reductions in plant height, plant fresh weight and leaf fresh weight but the leaf number, maximum root length, maximum blade width, root weight and stem weight in V. denseserrulata increased. The food utilization ratio of M. amblycephala was significantly higher when grazing solely on V. denseserrulata than when grazing on H. verticillata or the mixture. Our results imply that V. denseserrulata is protected from overgrazing by the ability of M. amblycephala to make more effective metabolic use of ingested material than for H. verticillata. Furthermore, M. amblycephala is beneficial to V. denseserrulata in reducing competition from H. verticillata.

scholarly journals Nguyen Duc Thanh∗, Nguyen Thi Kim Lien, Pham Quang Chung, Tran Quoc Trong, Le Thi Bich Thuy, and Henry Nguyen

2017 ◽  
Vol 23 (4) ◽  
pp. 323 ◽  
Author(s):  
Nguyen Duc Thanh ◽  
Nguyen Thi Kim Lien ◽  
Pham Quang Chung ◽  
Tran Quoc Trong ◽  
Le Thi Bich Thuy ◽  
...  
Keyword(s):  
Root Length ◽  
Upland Rice ◽  
Average Distance ◽  
Rice Genome ◽  
Root Traits ◽  
Root Weight ◽  
Deep Root ◽  
Maximum Root Length ◽  
Maximum Root ◽  
Drought Resistant

Upland rice grows on 19 million ha, about 15% of the world's rice plantation [2]. The production of upland rice is crucial to agricultural economy of many countries [15]. The yield of upland rice is very low with an average of about 1 t/ha. Drought is a major constraint to the productivity of upland rice. In this paper, we present the results on mapping QTLs for root traits related to drought resistance (maximum root length, root thickness, root weight to shoot and deep root weight to shoot ratios) in upland rice using a recombinant inbreed (RI) population derived from a cross between Vietnamese upland rice accessions. The first molecular linked of Vietnamese upland rice were constructed. The map consists of 239 markers (36 SSR and 203 AFLP markers) mapped to all 12 rice chromosomes. This map covered 3973.1 cM of rice genome with an average distance of 16.62 cM between the markers. Twenty three putative QTLs were detected. Among them, four QTLs for MRL, four QTLs for R/SR, four QTLs for DR/SR, two QTL for RN, two QTLs for RT, two for PH, and five QTLs for TN were recorded. There are several SSR markers such as RM250, RM270, RM263, RM242, RM221 linked to QTL regions. They could be very useful for drought resistant selection in rice. Some common QTLs for maximum root length and deep root weight to shoot ratio were observed in different genetic background (RDB09 × R2021 and IR64 × Azorean populations) and ecological locations (IRRI and Vietnam). These QTLs could be very useful for precise locating drought resistant gene(s) and marker-assisted selection.  

scholarly journals In Vitro Regeneration of Dendrobium sp. of Orchid Using Leaf Tip as Explant

2016 ◽  
Vol 8 (2) ◽  
pp. 75-78
Author(s):  
K Goswami ◽  
S Yasmin ◽  
KM Nasiruddin ◽  
F Khatun ◽  
J Akte
Keyword(s):  
In Vitro Regeneration ◽  
Plantlet Regeneration ◽  
Shoot Length ◽  
Ms Medium ◽  
Fresh Weight ◽  
Half Strength ◽  
Maximum Root Length ◽  
Maximum Root ◽  
Regenerated Plantlets

Plant growth regulators (PGRs) namely, 2,4-D, NAA and BAP were added into Murashige and Skoog (MS) medium to observe the effect of PGRs on the growth and development of Dendrobium sp. orchid. Leaf tips of Dendrobium sp. were used as explants and inoculated on MS medium supplemented with 2, 4 D (0, 0.5, 2.5, 5, 10 mgL?1) for development of PLBs. The maximum PLBs formation (90%) and the maximum number of PLBs (16.00) were observed in 10 mgL?1 2, 4-D into MS medium after 60 days of culture. Subcultured PLBs were inoculated on MS medium supplemented with different combinations of NAA (0, 0.5, 2.5, 5 mgL?1) and BAP (0, 0.5, 2.5, 5 mgL?1) for shoot regeneration. The maximum number of shoot (11.00), the highest fresh weight (0.6233g) and the highest shoot length (3.613 cm) were observed in 0.5 mgL?1 NAA + 0.5 mgL?1 BAP after 60 days of culture. Even, the maximum number of root (4.00), the maximum root length (1.627cm) and the maximum plantlet regeneration percentage (93.33%) were observed with the combined effect of 0.5 mg NAA and 0.5 mg BAP after 60 days of culture. Finally, regenerated plantlets were transferred into half strength MS medium to obtain plants.J. Environ. Sci. & Natural Resources, 8(2): 75-78 2015

scholarly journals Comparison of Early and Conventional Soybean Production Systems for Yield and other Agronomic Traits

2017 ◽  
Vol 1 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Ouertani Khaled ◽  
Evandrew Washington ◽  
Patricia Lage ◽  
Stella K. Kantartzi ◽  
David A. Lightfoot ◽  
...  
Keyword(s):  
Root Length ◽  
Lateral Root ◽  
Dry Weight ◽  
Fresh Weight ◽  
Soybean Production ◽  
Shoot Fresh Weight ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Maximum Root Length ◽  
Maximum Root

The early soybean production system (ESPS) was reported to be beneficial for yield compared to the conventional soybean production system (CSPS) and is widely used in the Southern USA. The objective of this study was to compare yield, yield components, root traits, and shoot traits in ESPS (April planting) and CSPS (June planting) in NC Sandhills using a recombinant inbred line (RIL) population, ‘Hartwig’ by ‘Flyer’ (n=92). The population was grown in Spring Lake, NC in 2008 at a density of 16 seeds m-2. The traits measured were days to germination, days to flowering, plant height, seed weight, seed number, pod number, harvest index, root fresh weight, root dry weight, shoot fresh weight, shoot dry weight, maximum root length, and lateral root number. The survival rate ranged from 83.7 to 90.22% for ESPS; however, it was 21.74% for CSPS. Significant differences were observed for almost all traits measured in ESPS (April) compared to CSPS (June) apart from fresh root weight and lateral root number. An average increase in flowering time of 9 days was observed in CSPS compared to ESPS. On the other hand, several traits showed a significant mean decrease in CSPS compared to ESPS as plant height by 41.96%, seed weight by 74.7%, harvest index by 73.3%, pod number by 65.2%, and seed number by 64.9%. The means for root fresh weight, root dry weight, shoot fresh weight, shoot dry weight, maximum root length, and lateral root numbers are shown in Table 2 for both ESPS and CSPS. The results indicated an average decrease of 40.4% in root fresh weight, of 70.2% in root dry weight, of 68.1% in shoot fresh weight, of 80.1% in shoot dry weight, and of 83.3% in maximum root length in CSPS compared to ESPS. However, lateral root numbers increased by an average of 12.7% in CSPS compared to ESPS. Therefore, CSPS may not be appropriate for soybean at least in NC Sandhills.

scholarly journals Study of indole butyric acid (IBA) effects on cutting rooting improving some of wild genotypes of damask roses (Rosa damascena Mill.)

2015 ◽  
Vol 60 (3) ◽  
pp. 263-275 ◽  
Author(s):  
Fardin Nasri ◽  
Arsalan Fadakar ◽  
Mahmood Saba ◽  
Bayzid Yousefi
Keyword(s):  
Butyric Acid ◽  
Control Treatment ◽  
Rosa Damascena ◽  
Indole Butyric Acid ◽  
Significant Difference ◽  
Maximum Root Length ◽  
Number Of Leaves ◽  
Maximum Root ◽  
Medicinal Properties ◽  
The Rose

Rosa damascena is very important for essential oil production, medicinal properties and it is also widely cultivated as a garden rose. The Rose species is mainly propagated by stem cutting. In the present study, the effect of different levels of 0, 500 and 1,000 mg l-1 (quick dip method for 20 s) of indole butyric acid (IBA) on the rooting of 12 wild genotypes (including: Kurdistan 1 to Kurdistan 12) of R. damascena was investigated. The results show that the rooting ability of R. damascena differs significantly between the twelve genotypes. The highest rooting (79.56%) and callus production (69.08%), number of roots (8.33), root fresh and dry weights (361.80 and 244.74 mg, respectively) were recorded in Kurdistan 5 genotype with 1,000 mg l-1 IBA. The maximum root length (5.84 cm) was observed in Kurdistan 5 genotype with 500 mg l-1 IBA that showed a significant difference compared to the control treatment (0.96 cm). The highest number of leaves per bud (7.33 at 500 mg l-1 IBA) and number of buds (5.00 at 1,000 mg l-1 IBA) were recorded in Kurdistan 1 genotype. The current study demonstrated that the different genotypes of R. damascena were in a difficult-toroot state, which suggests that cutting treatment with 1,000 mg l-1 IBA overcame the problem of the difficult-to-root state, and it can also enhance the rooting percentage in the studied genotypes.

scholarly journals Effects of Water Depth on the Growth of the Submerged Macrophytes Vallisneria natans and Hydrilla verticillata: Implications for Water Level Management

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2590
Author(s):  
Qisheng Li ◽  
Yanqing Han ◽  
Kunquan Chen ◽  
Xiaolong Huang ◽  
Kuanyi Li ◽  
...  
Keyword(s):  
Water Level ◽  
Water Depth ◽  
Deep Water ◽  
Submerged Macrophytes ◽  
Hydrilla Verticillata ◽  
Water Level Fluctuations ◽  
Total Biomass ◽  
Intermediate Water ◽  
Factors Affecting ◽  
Vallisneria Natans

Water level is one of the most important factors affecting the growth of submerged macrophytes in aquatic ecosystems. The rosette plant Vallisneria natans and the erect plant Hydrilla verticillata are two common submerged macrophytes in lakes of the middle and lower reaches of the Yangtze River, China. How water level fluctuations affect their growth and competition is still unknown. In this study, three water depths (50 cm, 150 cm, and 250 cm) were established to explore the responses in growth and competitive patterns of the two plant species to water depth under mixed planting conditions. The results show that, compared with shallow water conditions (50 cm), the growth of both submerged macrophytes was severely suppressed in deep water depth (250 cm), while only V. natans was inhibited under intermediate water depth (150 cm). Moreover, the ratio of biomass of V. natans to H. verticillata gradually increased with increasing water depth, indicating that deep water enhanced the competitive advantage of V. natans over H.verticillata. Morphological adaptation of the two submerged macrophytes to water depth was different. With increasing water depth, H. verticillata increased its height, at the cost of reduced plant numbers to adapt to poor light conditions. A similar strategy was also observed in V. natans, when water depth increased from 50 cm to 150 cm. However, both the plant height and number were reduced at deep water depth (250 cm). Our study suggests that water level reduction in lake restoration efforts could increase the total biomass of submerged macrophytes, but the domination of key plants, such as V. natans, may decrease.

scholarly journals Monosporic Inoculation of Economically Important Horticultural Species with Native Endomycorrhizae under Greenhouse Conditions

Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 130
Author(s):  
Flor Hernandez ◽  
Rosalinda Villarreal ◽  
Valentin Torres ◽  
Adrien Gallou
Keyword(s):  
Mycorrhizal Fungi ◽  
Agricultural Intensification ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Phosphorus Concentration ◽  
Root Weight ◽  
Fresh Weight ◽  
Flower Number ◽  
Total Dry Weight ◽  
Total Fresh Weight

Research into the symbiotic relationship between plants and arbuscular mycorrhizal fungi (AMF) is key for sustainable agricultural intensification. The objective of the present study is to evaluate native AMF at the monosporic level in greenhouse-grown, economically important crops. Agricultural soil samples from three locations (Saltillo, Zaragoza, and Parras) were obtained by combining portions resulting from a zigzag sampling pattern. From these samples, 15 morphotypes were extracted according to a modified Gerdemann’s technique and monosporically inoculated on melon, cucumber, tomato, and onion, 30 days after their sowing. Under a completely random experimental design, 16 treatments with three repetitions were defined. Plant height, root length, stem diameter, total fresh weight, fresh root weight, dry root weight, bulb weight, fresh leaf weight, total dry weight, flower number, leaf number, fruit number, spore number, and percentage of colonization were all evaluated. The results were subjected to the analysis of variance (ANOVA) and the Tukey comparison test (p ≤ 0.05), which showed that the monosporic inoculation favors significantly the AMF and the host, while the T6 (Saltillo spore + Steiner modified with 20% of the normal phosphorus concentration) showed a greater response uniformity on onion and melon, which indicates its great potential as an inoculum.

scholarly journals Sustainable and Ecofriendly Approach of Managing Soil Born Bacterium Ralstonia solanacearum (Smith) Using Dried Powder of Conyza canadensis

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 327
Author(s):  
Ke Chen ◽  
Raja Asad Ali Khan ◽  
Wen Cao ◽  
Meng Ling
Keyword(s):  
Bacterial Population ◽  
Conyza Canadensis ◽  
Plastic Mulch ◽  
Fresh Biomass ◽  
Plastic Mulching ◽  
Maximum Root Length ◽  
Maximum Root ◽  
Dose Experiment ◽  
Mulching Duration

Bacterial wilt disease caused by Ralstonia solanacearum is a devastating plant disease that inflicts heavy losses to the large number of economic host plants it infects. The potential of dried powder of the Conyza canadensis to control bacterial wilt (BW) of tomato was explored in vitro and in planta. Three application times (16 days before transplanting (DBT), 8 DBT and 0 DBT), three plastic-mulch durations (10 days plastic mulching (DPM), 5DPM and 0DPM) and four doses viz. 0 g, 8 g, 16 g and 24 g of the plant powder were evaluated. SEM analysis was also conducted to observe the change in bacterial cell morphology. Ethanol extract of dried C. canadensis in different concentrations inhibited the in vitro growth of R. solanacearum by as much as 98% of that produced by ampicillin. As evident from the scanning electron micrograph, the highest concentration produced severe morphologic changes, such as rupture of the bacterial cell walls and cell contents leaked out. Results from application time and dose experiment demonstrated that the highest powder dose viz. 24 g kg−1 mixed with infested soil 16 DBT gave maximum root length (34.0 ± 2.5 cm), plant height (74.3 ± 4.7 cm), fresh biomass (58.3 ± 4.3 g), reduction in bacterial population (1.52 log10) and resulted in lowest AUDPC value (1156.6). In case of mulching duration and dose experiment the maximum root length (39.6 ± 3.2 cm), plant height (78.3 ± 5.8 cm), fresh biomass (65.6 ± 4.9 g) reduction in bacterial population (1.59 log10) and lowest AUDPC value (1251.6) was achieved through the application of highest powder dose viz. 24 g kg−1 and longest plastic mulching duration of 10 DPM. The better results of highest dose and longer application time can be explained on the basis of higher amounts of anti-microbial plant bio-active compounds in highest dose and the longer exposure time of the pathogen to these chemicals. The better results of longer mulching duration are due to faster and more complete decomposition (because of 10-days-long plastic-mulch-provided increased solar heat) of the dried powder which produced more amounts of volatile and non-volatile bactericidal compounds. Our results clearly suggest that the use of 24 g kg−1 dried plant powder of C. canadensis plastic-mulched for two weeks could be used as a reliable component of the integrated disease management program against BW.

Effects of Prodiamine on Tall Fescue (Festuca arundinacea) Rooting

1995 ◽  
Vol 9 (4) ◽  
pp. 736-740
Author(s):  
Sangwook Han ◽  
Thomas W. Fermanian ◽  
Thomas B. Voigt
Keyword(s):  
Tall Fescue ◽  
Root Length ◽  
Dry Weight ◽  
Kentucky Bluegrass ◽  
Individual Response ◽  
Root Dry Weight ◽  
Significant Difference ◽  
Maximum Root Length ◽  
Maximum Root ◽  
The Mean

With the increased development of new tall fescue cultivars used in turf, it is important to understand their individual response to herbicide treatment. The effect of prodiamine on tall fescue root dry weight and root length of selected tall fescue cultivars was studied in the greenhouse in 1.3-m-deep pots of calcined clay. Prodiamine at 0.8 kg ai/ha did not significantly affect either root dry weight or root length. However, the mean root dry weight and maximum root length averaged over all cultivars were significantly reduced at 4 wk after treatment with 1.7 kg/ha. When the prodiamine treatments were repeated in a second experiment, both rates caused a significant reduction in the mean root dry weight and maximum root length but there was no significant difference between prodiamine rates. Single degree of freedom contrasts between the untreated and treated turfs for each cultivar had some differential response in root dry weight. The reduction in root dry weight in the prodiamine treatments was more pronounced in the second study because the turf was less mature. ‘Olympic’ and ‘Rebel’ tall fescue had significantly reduced root dry weight at the 1.7 kg/ha rate in first study; whereas, ‘Amigo,’ Olympic, ‘Sundance,’ and ‘Taurus' tall fescue had significant reduction in root dry weight at both 0.8 and 1.7 kg/ha prodiamine rates. ‘Midnight’ Kentucky bluegrass had significantly reduced root length at both prodiamine rates in the second experiment but in general there was little difference among tall fescue cultivars treated with prodiamine.

Genetic variation amongst swede varieties and their hybrids and their response to soil fertility

1976 ◽  
Vol 87 (2) ◽  
pp. 443-446 ◽  
Author(s):  
O. A. Denton ◽  
W. J. Whittington
Keyword(s):  
Dry Matter ◽  
Total Yield ◽  
Gene Interaction ◽  
Matter Content ◽  
Root Weight ◽  
Environment Interaction ◽  
Dry Matter Content ◽  
Fresh Weight ◽  
Partial Dominance ◽  
Shoot Weight

SummaryThe mean total yield and mean fresh weight of seven swede varieties and their F1 hybrids was increased primarily by nitrogen and also by phosphorus fertilizer. There was no evidence of genotype × environment interaction for characters concerned with yield except for dry-matter content where two varieties, Best-of-All and Reform, were less stable to fertility environments than the others. Heterosis was common amongst F1 hybrids and this suggests their use in swede improvement: the inheritance pattern of root weight showed overdominance, shoot weight showed partial dominance and drymatter content showed additivity, with no evidence of gene interaction. Segregation for root fresh weight and dry-matter content occurred in F2 populations and although an overall negative correlation was found there was evidence that progeny from certain crosses gave reasonable prospects of combining both characters.

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