Cultivation of Edible Tropical Bolete, Phlebopus spongiosus, in Thailand and Yield Improvement by High-Voltage Pulsed Stimulation

Tropical bolete, Phlebopus spongiosus, is an edible ectomycorrhizal mushroom indigenous to northern Thailand. This mushroom has the ability to produce fruiting bodies without the need for a host plant. In this study, the technological cultivation of P. spongiosus was developed. Cultivation experiments indicated that fungal mycelia could completely colonize the cultivation substrate over a period of 85–90 days following inoculation of liquid inoculum. Primordia were induced under lower temperatures, high humidity and a 12-h photoperiod. Mature fruiting bodies were developed from young fruiting bodies within a period of one week. Consequently, yield improvement of P. spongiosus cultivation was determined by high-voltage pulsed stimulation. The results indicated that the highest degree of primordial formation, number of mature fruiting bodies and total weight values were obtained in cultivation experiments involving a high voltage of 40 kV. The total weight of the mushrooms increased by 1.4 times after applying high-voltage pulses when compared with the control. Additionally, the results revealed that the size of the fruiting body and the proximate composition of the fruiting bodies from high-voltage stimulation treatments were not different from the control. This research provides valuable information concerning successful cultivation techniques and yield improvement by high-voltage pulsed stimulation for the large-scale commercial fruiting body production of P. spongiosus.

Path analysis based on genetic association of yield components and insects pest in upland cotton varieties

Gossypium hirsutum L. is also called upland cotton or Mexican cotton. It is the most widely cultivated species of cotton in the whole world. Globally, about 90% of all cotton production comes from the cultivars derived from this species. Some genetic parameters like monopodial branches per plant, sympodial branches per plant, sympodial branch length, bolls per plant, boll weight, sympo-boll distance, Ginning Out Turn%, staple length (rg = 0.9199**), and fiber strength along with seed cotton yield were evaluated for their potential utilization via selection in seed cotton yield improvement. Significant positive genetic correlations were estimated for monopodial branches per plant (rg = 0.9722**), sympodial branches per plant (rg = 0.7098**), sympodial branch length (rg = 0.617**), bolls per plant (rg = 0.8271**), boll weight (rg = 0.8065**), sympo-boll distance (rg = 0.6507**), Ginning Out Turn (GOT)% (rg = 0.7541**), staple length (rg = 0.9199**), and fiber strength (rg = 0.7534**) with seed cotton yield. A path analysis of all the yield traits under study revealed strong positive direct effects of monopodial branch length (1.1556), sympo-boll distance (0.8173) and staple length (0.7633), while plant height exerted a highly strong direct negative effect (-1.2096) on yield. It is concluded that a direct selection based on monopodial branch length and sympo-boll distance, and staple length is effective, whereas, monopodial branch length, and sympodial branch length are good selection indicators via bolls per plant for yield improvement in cotton.

Yield is negatively correlated with nucleotide-binding leucine-rich repeat gene content in soybean

The availability of increasing quantities of crop pangenome data permits the detailed association of gene content with agronomic traits. Here, we investigate disease resistance gene content of diverse soybean cultivars and report a significant negative correlation between the number of NLR resistance (R) genes and yield. We find no association between R-genes with seed weight, oil or protein content, and we find no correlation between yield and the number of RLK, RLP genes, or the total number of genes. These results suggest that recent yield improvement in soybean may be partially associated with the selective loss of NLR genes. Three quarters of soybean NLR genes do not show presence/absence variation, limiting the ability to select for their absence, and so the deletion or disabling of select NLR genes may support future yield improvement.

The Research on Total Factor Productivity of Soybean in China

This paper uses the panel stochastic frontier model to study the total factor productivity of Chinese soybean. The research shows that the impact of direct cost and labor cost on yield is positive and significant, the impact of indirect cost on yield is not significant, and the impact of cash cost on yield improvement is negative.

Uncovering and Engineering a Mini-Regulatory Network of the TetR-Family Regulator SACE_0303 for Yield Improvement of Erythromycin in Saccharopolyspora erythraea

Erythromycins produced by Saccharopolyspora erythraea have broad-spectrum antibacterial activities. Recently, several TetR-family transcriptional regulators (TFRs) were identified to control erythromycin production by multiplex control modes; however, their regulatory network remains poorly understood. In this study, we report a novel TFR, SACE_0303, positively correlated with erythromycin production in Sac. erythraea. It directly represses its adjacent gene SACE_0304 encoding a MarR-family regulator and indirectly stimulates the erythromycin biosynthetic gene eryAI and resistance gene ermE. SACE_0304 negatively regulates erythromycin biosynthesis by directly inhibiting SACE_0303 as well as eryAI and indirectly repressing ermE. Then, the SACE_0303 binding site within the SACE_0303-SACE_0304 intergenic region was defined. Through genome scanning combined with in vivo and in vitro experiments, three additional SACE_0303 target genes (SACE_2467 encoding cation-transporting ATPase, SACE_3156 encoding a large transcriptional regulator, SACE_5222 encoding α-ketoglutarate permease) were identified and proved to negatively affect erythromycin production. Finally, by coupling CRISPRi-based repression of those three targets with SACE_0304 deletion and SACE_0303 overexpression, we performed stepwise engineering of the SACE_0303-mediated mini-regulatory network in a high-yield strain, resulting in enhanced erythromycin production by 67%. In conclusion, the present study uncovered the regulatory network of a novel TFR for control of erythromycin production and provides a multiplex tactic to facilitate the engineering of industrial actinomycetes for yield improvement of antibiotics.