The primary objective of this work was to generate species-specific information about root architectural adaptation to variation in boron (B) availability at the onset of storage root formation among three sweetpotato [Ipomoea batatas (L.) Lam] cultivars (Beauregard = BX; Murasaki = MU; Okinawa = OK). Three B levels were used: 0B (B was omitted in the nutrient solution, substrate B = 0.1 mg·kg−1), 1XB (sufficient B; 0.5 mg·kg−1), and 2XB (high B; 1 mg·kg−1). The check cultivar BX showed evidence of storage root formation at 15 days in 0B and 1XB, whereas cultivars MU and OK failed to show evidence of root swelling. The 1XB and 2XB levels were associated with 736% and 2269% increase in leaf tissue B in BX, respectively, relative to plants grown in 0B. Similar magnitudes of increase were observed in MU and OK cultivars. There were no differences in adventitious root (AR) count within cultivars but OK showed 25% fewer AR numbers relative to BX across all B levels. 0B was associated with 20% and 48% reduction in main root length in BX and OK, respectively, relative to plants grown in 1XB and 2XB. 2XB was associated with a 10% increase in main root length in MU relative to plants grown in 0B and 1XB. 0B was associated with reduced lateral root length in all cultivars but the magnitude of responses varied with cultivars. These data corroborate findings in model systems and well-studied crop species that B deficiency is associated with reduced root growth. These data can be used to further understand the role of cultivar-specific responses to variation in B availability in sweetpotato.
Arthur Villordon and Jeffrey C. Gregorie
Hsuan Chen and Dennis J. Werner
Eastern redbud (Cercis canadensis L.) is a commonly used small landscape tree. Compact growth, purple leaf color, and weeping architecture are three popular ornamental phenotypes. Inheritances of weeping architecture and purple leaves have been reported previously. Inheritance of compact growth habit and its genetic linkage with the weeping and purple leaf genes have not been reported. In the present research, the inheritance of compact growth derived from ‘Ace of Hearts’ was explored in the F1, F2, and reciprocal backcross families resulting from the controlled hybridization of ‘Ruby Falls’ (normal growth/weeping architecture/purple leaf) × ‘Ace of Hearts’ (compact growth/nonweeping architecture/green leaf). All 27 F1 individuals were nonweeping, green-leaved, and noncompact. A total of 572 F2 progeny were obtained, and subsequent analysis of segregation revealed a single recessive gene controlled compact growth habit. Analysis of reciprocal backcross families confirmed this result as well. Weeping architecture and purple leaf color were also controlled by single recessive genes, confirming findings presented in previous studies in another redbud family. No linkage between the three genes was detected. This research is the first to report the inheritance of compact growth in eastern redbud and confirms independent assortment between the compact, purple leaf, and weeping genes.
Stephanie J. Walker, Paul Funk, Israel Joukhadar, Tom Place, Charles Havlik, and Bradley Tonnessen
Tong Zhang, Zheng Zhang, Qi Qiao, Wei Liu, and Xiaogai Hou
Paeonia ostii is recognized as an important oilseed tree peony species with potential as a raw material source for cosmetic and health care products, strong seed setting capacity, high seed oil yield, and abundant omega-3 polyunsaturated fatty acids. P. ostii, commonly called Fengdan, is widely cultivated in China. The cultivation method difference has an important influence on the oil-use feature, which is a key index for evaluating the quality of oilseed crops. This study aimed to select an optimal cultivation method to provide the first reference data for high-yield and high-quality seed oil harvesting and to facilitate the understanding of the quality difference in the formation mechanism of seed oil in cultivated P. ostii. This study selected five representative cultivation methods, open field cultivation, sunny slope cultivation, shady slope cultivation, understory intercropping cultivation, and high-altitude cultivation, and investigated the influence of cultivation method differences on the oil-use feature based on the three aspects of seed yield traits, oil yield, and fatty acid compositions. Six seed yield traits (fruit pod length, fruit pod width, fruit pod thickness, number of fruit pods per plant, 1000-grain weight, and seed yield per plant) and oil yield reached the maximum values of 7.75 cm, 6.99 cm, 1.57 cm, 11.33, 290.45 g, 85.8 g, and 30.41%, respectively, using the understory intercropping cultivation method. Fatty acid compositions were mainly identified as α-linolenic acid, linoleic acid, oleic acid, stearic acid, and palmitic acid, with significant content differences among different cultivation methods (P < 0.05). Functional component α-linolenic acid and total amounts of unsaturated fatty acids reached the maximum values of 46.85% and 65.23%, respectively, with high-altitude cultivation and understory intercropping cultivation. The seed yield traits, oil yield, and total amounts of unsaturated fatty acids were optimal with the understory intercropping cultivation method, whereas high-altitude cultivation was conducive to the accumulation of α-linolenic acid. Understory intercropping cultivation with appropriate altitude increases is recommended as a preponderant cultivation method for high-yield and high-quality seed oil harvesting for this crop.
Sofia Flores, Marlon Retana-Cordero, Paul R. Fisher, Rosanna Freyre, and Celina Gómez
The objectives were to 1) compare growth and yield of different ginger (Zingiber officinale) and turmeric (Curcuma longa) propagules grown under two photoperiods (Expt. 1); and 2) evaluate whether their growing season could be extended with night interruption lighting (NI) during the winter (Expt. 2). In Expt. 1, propagules included 1) micropropagated tissue culture (TC) transplants, 2) second-generation rhizomes harvested from TC transplants (2GR), and 3) seed rhizomes (R). Plants received natural short days (SDs) or NI providing a total photon flux density (TPFD) of 1.3 µmol·m−2·s−1. Providing NI increased number of new tillers or leaves per plant, rhizome yield (i.e., rhizome fresh weight), and dry mass partitioning to rhizomes in both species. There was no clear trend on SPAD index in response to photoperiod or propagative material. Although TC-derived plants produced more tillers or leaves per plant, 2GR ginger and R turmeric produced a higher rhizome yield. In Expt. 2, seed rhizomes of ginger and turmeric were grown under five treatments with different photoperiods and/or production periods: 1) 20 weeks with NI (20NI), 2) 24 weeks with NI (24NI), 3) 28 weeks with NI (28NI), 4) 14 weeks with NI + 10 weeks under natural SDs (24NISD), and 5) 14 weeks with NI + 14 weeks under natural SDs (28NISD). NI provided a TPFD of 4.5 µmol·m−2·s−1. Lengthening the production period and providing NI increased rhizome yield and crude fiber content in both species. SPAD index decreased when plants were exposed to natural SDs at the end of the production period (NISD treatments). Results demonstrate the potential to overcome winter dormancy of ginger and turmeric plants with NI, enabling higher rhizome yield under natural SDs.
Toktam Taghavi, Alireza Rahemi, Reza Rafie, and Maru K. Kering
Rapid multiplication of turmeric (Curcuma longa) by micropropagation is needed to produce a continuous source of uniformly sized, high-quality, and disease-free plantlets. Three in vitro experiments were conducted to optimize the medium by evaluating nine media and a full factorial combination (matrix) of two plant growth regulators for direct organogenesis of ‘Hawaiian Red’ turmeric. Two experiments evaluated the media, and the third studied the plant growth regulator matrix. As a result, Driver and Kuniyuki walnut (DKW), Murashige and Skoog (MS), and broadleaf tree basal (BLT) media performed better than woody plant media [Lloyd & McCown woody plant basal medium (L&M), and McCown’s woody plant basal salt mixture (McCown)] for shoot and root formation. The multiplication rate was 18 plants per explant in DKW with 1 mg⋅L−1 6-benzylaminopurine (BAP) and 0.1 mg⋅L−1 1-naphthaleneacetic acid (NAA). After transferring the plants to an ex vitro environment, the survival rate was 97%, and 30% higher than previously reported. DKW produced the highest number of plantlets (with shoots and roots), and BLT produced fewer plants with higher biomass. In the MS media, higher BAP to NAA ratio (2.5 to 0.1 mg⋅L−1) produced the most significant number of shoots; however, the lowest concentration of BAP and NAA (0.1 mg⋅L−1 of both) produced the highest number of rooted plantlets. There are two recommendations for tissue culture of ‘Hawaiian Red’ turmeric. To produce the highest number of plantlets, one should use the higher BAP to NAA ratio (2.5 mg⋅L−1 BAP and 0.1 mg⋅L−1 NAA) for shoot proliferation and then transfer the explants to the root initiation media. However, to reduce the number of subcultures, the explants can be grown in the lowest concentration of both BAP and NAA (0.1 mg⋅L−1) to induce both shoot and root. Although, the number of plantlets (with roots and shoots) will decrease in this method, there is no need for subsequent subcultures and changing of the plant growth regulator combinations.
James M. Orrock, Brantlee Spakes Richter, and Bala Rathinasabapathi
Tea (Camellia sinensis) is a promising new specialty crop for production in Florida. However, few data exist on the establishment phase of tea plantings in this environment and on how early growth parameters may predict yield potential. We tested seven accessions of tea grown under field conditions in north-central Florida for leaf yield and growth parameters—namely, pruned biomass, trunk diameter, trunk height, trunk width, trunk height × width, and canopy area—in the second and third years after planting. Our analyses indicated that the accession Fairhope performed best overall. Pruned biomass and trunk diameter were the best predictors for leaf yield. The harvested leaves produced good-quality black tea, with caffeine levels comparable to commercially available tea. These data indicate that nondestructive measurements of growth can be useful to assess yield potential of tea, and that regionally adapted tea accessions can be identified during the establishment stage.
Rhuanito Soranz Ferrarezi and Tzu Wei Peng
Precision agriculture involves applying artificial intelligence, computers, sensors, and automation to improve crop field productivity while monitoring environmental conditions to conserve soil, water, and other natural resources focusing on agricultural sustainability. Despite many applications in agriculture, data monitoring and recording technologies have limited use due to the price. Low-cost open-source systems, like the ones available with the Internet of things (IoT) world, can potentially be developed as a universal-fit and cloud-connected technology for multiple applications. We designed and built a basic data collecting system using a commercial standalone embedded computer with Python programming language, serial data interface (SDI)-12/analog sensor adaptor, and digital sensors to monitor soil moisture and transmit the data remotely. SDI-12 is a standard communication protocol that transfers digital sensor measurements to a data recorder. We set up a pilot study that automatically collected and uploaded the data into the Internet to allow remote data transfer and access. The system performed reliably over 1 week with potting soil under field conditions without maintenance and successfully recorded data in real-time. The volumetric water content ranged from 0.03 to 0.23 m3·m−3, dielectric permittivity from 3.3 to 18.9 (unitless), EC from 0.0 to 0.3 dS·m−1, and soil temperature from 20.7 to 44.8 °C. All the data were successfully collected and uploaded to the cloud every 20 min, allowing users to remotely monitor the data using a free online application. However, heavy rainfall and high insolation could damage the system through excessive moisture or overheating, requiring a waterproof and heavy-duty protection case. The ThingSpeak channel allows customizing to suit a user’s specific requirements or adding more features for further development, such as automated irrigation, which can improve irrigation and fertilization efficiency by applying water and fertilizers at the right time based on sensor readings.
Shannon Rauter, Youping Sun, and Melanie Stock
In response to the growing demand for specialty cut flowers, floral crops are increasingly produced in semiarid areas where soil salinity can impact crop timing, reduce stem length, and decrease yield. The goal of this study was to investigate the salinity sensitivity of ‘Carmel’ and ‘Galilee’ anemone (Anemone coronaria), and ‘Amandine’ and ‘LaBelle’ ranunculus (Ranunculus asiaticus) with respect to physiological characteristics and marketable yield. Nine plants were irrigated weekly for 8 weeks with a nutrient (control) solution with an electrical conductivity (EC) of 0.5 dS⋅m–1 or saline solutions prepared by adding sodium chloride and calcium chloride dihydrate to a nutrient solution to obtain an EC of 1.5, 2.5, 3.5, 4.5, or 5.5 dS⋅m–1. Yield was evaluated by dividing stems into marketable and cull grades based on length and bloom quality. At the end of the study, the visual quality of the plants was scored, and gas exchange data were collected using a portable photosynthesis system. Cultivars of each species responded similarly, and marketable yields were low across all treatments, with average marketable yields (mean ± sd) of 1.7 ± 0.6 stems/plant for anemone and 1.2 ± 0.1 stems/plant for ranunculus. Visual quality (0–5 scale, with 0 = dead and 5 = excellent) decreased from 3 to 1 for anemone and 3 to 2 for ranunculus as EC increased from 0.5 to 4.5 dS⋅m–1 and 0.5 to 5.5 dS⋅m–1, respectively. Anemone leaf greenness decreased by 48%, stomatal conductance (g S) decreased by 79%, transpiration (E) decreased by 75%, and net photosynthesis (Pn) decreased by 92% when irrigation solution EC increased from 0.5 to 4.5 dS⋅m–1. The ranunculus growth index decreased by 17%, leaf greenness decreased by 45%, and E decreased by 23% as irrigation solution EC increased from 0.5 to 5.5 dS⋅m–1. Both anemone and ranunculus can be considered sensitive to salinity, indicating the importance of careful soil management in cut flower production systems in semiarid areas that are at risk for elevated soil salinity.
Fang Xu, Junqin Zong, Jingbo Chen, Jianjian Li, Dandan Li, Jianxiu Liu, and Fang Xu
A static experiment in greenhouse was conducted to investigate the growth of three grasses in high and medium eutrophic water and the effects of their removal on ammonia nitrogen (NH4 +-N), nitrate nitrogen (NO3 −-N), total nitrogen (TN), total phosphorus (TP), and the chemical oxygen demand (COD), and compared with cattail (Typha angustifolia). The results showed that 1) the removal efficiency of NH4 +-N, NO3 −-N, TN, TP, and COD treated by the four plants in eutrophic water were significantly higher than that in non-plant water. With the extension of treatment time, the concentrations of NH4 +-N, NO3 −-N, TN, TP, and COD in the eutrophic water decreased first and then tend to be stable. 2) Cynodon dactylon ‘Tifton 85’ (C. dactylon ‘Tifton 85’), Cortaderia selloana ‘Pumila’ (C. selloana ‘Pumila’) and T. angustifolia absorbed more than 95.7% and 88.6% of TN and TP in eutrophic water, and accumulate more than 89.5% and 82.0% in plants, respectively. However, the ratio of Cortaderia selloana ‘Silver Comet’ (C. selloana ‘Silver Comet’) was significantly lower. 3) The high abilities of these three plants to purify eutrophic water may be directly related to their rapid growth. 4) The comprehensive purification ability of the four plants to eutrophic was significantly different, in the order of C. dactylon ‘Tifton 85’ > C. selloana ‘Pumila’ ≈ T. angustifolia > C. selloana ‘Silver Comet’. These results indicated that C. dactylon ‘Tifton 85’ and C. selloana ‘Pumila’ can be used as alternative plants to T. angustifolia for the purification of eutrophic water. The results of this study can provide new materials and ideas for phytoremediation.