Baby Cassava: An Alternative Marketing Strategy for Freshly Cut Cassava

There are many procedures for obtaining minimally processed fruits and vegetables, aiming at adding value and maintaining the quality for a longer period. Cassava is a root that adapts to minimum processing technology, because the tissues are more resistant, what helps in obtaining different cut shapes and formats. However, it is a root susceptible to browning and microbiological contamination. In this chapter, methodologies and procedures are described to obtain alternative formats for minimally processed cassava, which was generally denominated “babycassava”, called “babytolete”, “cateto”, and “rubiene”. Besides that, some preharvest and postharvest factors that influence the shape and quality of “babycassava” formats will be addressed. It was verified that preharvest factors could influence the quantitative and qualitative aspects, resulting in browning of the minimally processed root. Some of the factors studied seem to regulate key enzymes in which they mediate oxidative reactions that cause browning, such as polyphenol oxidase and peroxidase, and other enzymes that participate in the reactive oxygen species (ROS) elimination process. In this way, the turning stage of “babycassava” manufacturing removes the parenchyma, minimizing the effect of browning-related enzymes

Unraveling how an auxin signaling mutation affects the xylem hydraulic efficiency and safety in tomato

Auxins are known to regulate xylem development in plants, however, their effects on water transport efficiency and hydraulic safety are poorly known. Here we used tomato plants of the diageotropica mutant (dgt), which has impaired function of a Cyclophilin 1 cis/trans isomerase involved in auxin signaling, and its corresponding wild type (WT), to explore its effects on plant hydraulics and leaf gas exchanges. The xylem conduits of dgt showed a reduced hydraulically-weighted vessel diameter (D h ) (24-43%) and conduit number (25-58%) in petioles and stems, resulting in lower theoretical hydraulic conductivities (K t ). On the other hand, no changes in root D h and K t were observed. In addition, the measured stem and leaf hydraulic conductances of dgt agreed with the K t values and were lower (up to 81%). Despite dgt and WT showing similar root D h and K t , the measured root hydraulic conductance of dgt was 75% lower. The dgt mutation increased the vein (D v ) and stomata density (D s ), which could potentially increase photosynthesis. Nevertheless, even presenting the same photosynthetic capacity of WT plants, the dgt showed a photosynthetic rate c. 25% lower, coupled with a stomatal conductance reduction of 52%. These results clearly demonstrate that increases in D v and D s only result in higher leaf gas exchange when accompanied by higher hydraulic efficiency. The dgt also showed higher wall thickness per conduit diameter ratio (t/b) 3 , without major modifications in the pit membranes and cell wall reinforcement. The changes in xylem architecture resulted in a more negative Ψ 50 (water potential of 50% loss hydraulic conductivity), with a difference of 0.25 MPa and an increase of 64% in hydraulic safety margin comparison with WT plants. Under water deficit, dgt took twice as many days to reach Ψ 50 (-1.34±0.06 MPa) and half the time after rehydration to recover gas exchange when compared with WT (Ψ 50 = -1.14±0.08 MPa). To confirm that the improved 50 of dgt was functionally significant, we exposed WT plants to a more intense water deficit (equivalent to dgt’s Ψ 50 ) and, indeed, WT plants did not show photosynthetic recovery under this condition. Therefore, we demonstrate that the changes in the xylem as a function of the mutation in auxin perception result in a severe reduction on in hydraulic efficiency and increased hydraulic safety. Keywords: Ailsa Craig. Gas exchange. Solanum lycopersicum. Water deficit. Water transport. Xylem anatomy.As auxinas são conhecidas por regular o desenvolvimento do xilema nas plantas, entretanto, seus efeitos sobre a eficiência do transporte de água e segurança hidráulica são pouco conhecidos. Aqui usamos plantas mutantes de tomateiro diageotropica (dgt), que tem a função prejudicada de uma ciclofilina 1 cis/trans isomerase envolvida na sinalização da auxina, e seu correspondente tipo selvagem (WT), para explorar seus efeitos na hidráulica de plantas e nas trocas de gasosas foliares. O xilema do dgt apresentou menor diâmetro de vaso (D h ) (24-43%) e número de condutos (25-58%) em caule e pecíolo, resultando em menores condutividades hidráulicas teóricas (K t ). Por outro lado, não foram observadas alterações de D h e K t nas raízes. Além disso, as condutâncias hidráulicas medidas no caule e folha do dgt concordaram com os valores de K t e foram mais baixas (até 81%). Apesar de dgt e WT apresentarem D h e K t similares nas raízes, a condutância hidráulica da raiz medida no dgt foi 75% menor. A mutação dgt aumentou a densidade das veias (D v ) e estômatos (D s ), o que potencialmente aumentaria a fotossíntese. No entanto, mesmo apresentando a mesma capacidade fotossintética das plantas WT, o dgt mostrou uma taxa fotossintética c. 25% menor, juntamente com uma redução da condutância estomática de 52%. Estes resultados demonstram claramente que os aumentos em D v e D s só resultam em maiores taxa de trocas gasosos foliares quando acompanhados de maior eficiência hidráulica. O dgt também mostrou maior razão espessura da parede por diâmetro de conduto (t/b) 3 , sem grandes modificações nas membranas de pontuação e no reforço da parede celular. As mudanças na arquitetura do xilema resultaram em Ψ 50 (potencial hídrico de 50% de perda de condutividade hidráulica) mais negativos, com uma diferença de 0,25 MPa e um aumento de 64% na margem de segurança hidráulica em comparação com as plantas WT. Sob a seca, a dgt levou o dobro dos dias para chegar ao Ψ 50 (-1,39±0,06 MPa) e metade do tempo após a reidratação para recuperar as trocas gasosas quando comparado com a WT (Ψ 50 = 1,14±0,08 MPa). Para confirmar que a redução do Ψ 50 do dgt foi funcionalmente significativo, expusemos as plantas WT a uma seca mais intensa (equivalente ao Ψ 50 do dgt) e, de fato, as plantas WT não mostraram recuperação fotossintética sob esta condição. Portanto, demonstramos que as mudanças no xilema em função da mutação na percepção da auxina resultam em uma redução severa na eficiência hidráulica e no aumento da segurança hidráulica. Palavras-chave: Ailsa Craig. Anatomia do xilema. Deficit hídrico. Solanum lycopersicum. Transporte de água. Trocas de gasosas.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Initial growth of cassava plants cv. Mossoró under different water regimes

The sprouting phase of cassava is critical for the establishment of the plant, with this phase being dependent on soil moisture. As such, this study evaluated the effect of different irrigation levels on the initial growth of cassava cv. Mossoró in semi-arid conditions. The experiment was conducted under completely randomized design conditions with 5 replications. The treatments in pots containing one plant per experimental unit consisted of 5 irrigation levels, 0, 25, 50, 75 and 100% of the reference evapotranspiration (ETo, mm day-1), which corresponded to totals for the experimental period of 11.20; 42.15; 73.09; 104.03 and 134.97 mm, respectively. At 30 days after planting, the number of leaves and stems, as well as the dry mass of the shoot and the root had increased sharply for irrigation levels up to 73.09 mm. For higher irrigation levels there was a tendency for plant growth stabilization; however, above 104.03 mm there was a decrease. Shoot and root dry mass ratio showed severe water stress at the 11.20 mm level, being more damaging to root growth. Plant height showed a positive linear trend as the level of irrigation was increased, as opposed to water use efficiency. Therefore, irrigation with 50% replacement of ETo (73.09 mm) provided the best conditions for early growth of cassava

Initial growth of cassava plants cv. Mossoró under different water regimes = Crescimento inicial de plantas de mandioca cv. Mossoró sob diferentes regimes hídricos

The sprouting phase of cassava is critical for the establishment of the plant, with this phase being dependent on soil moisture. As such, this study evaluated the effect of different irrigation levels on the initial growth of cassava cv. Mossoró in semi-arid conditions. The experiment was conducted under completely randomized design conditions with 5 replications. The treatments in pots containing one plant per experimental unit consisted of 5 irrigation levels, 0, 25, 50, 75 and 100% of the reference evapotranspiration (ETo, mm day-1), which corresponded to totals for the experimental period of 11.20; 42.15; 73.09; 104.03 and 134.97 mm, respectively. At 30 days after planting, the number of leaves and stems, as well as the dry mass of the shoot and the root had increased sharply for irrigation levels up to 73.09 mm. For higher irrigation levels there was a tendency for plant growth stabilization; however, above 104.03 mm there was a decrease. Shoot and root dry mass ratio showed severe water stress at the 11.20 mm level, being more damaging to root growth. Plant height showed a positive linear trend as the level of irrigation was increased, as opposed to water use efficiency. Therefore, irrigation with 50% replacement of ETo (73.09 mm) provided the best conditions for early growth of cassava. = A fase de brotação da mandioca é crítica para o estabelecimento da cultura, sendo esta fase dependente da umidade do solo. Assim, esse estudo teve como objetivo avaliar a influência de diferentes lâminas de irrigação no crescimento inicial de mandioca cv. Mossoró em condições de semiárido. O experimento foi conduzido em delineamento inteiramente casualisado, com 5 repetições. Os tratamentos consistiram de 5 lâminas de irrigação, sendo 0, 25, 50, 75 e 100% da evapotranspiração de referência (ETo, mm dia-1), que corresponderam a um total de 11,20; 42,15; 73,09; 104,03 e 134,97 mm durante o período experimental, em vasos contendo uma planta por unidade experimental. Aos 30 dias após o plantio, verificouse que o número de folhas e de hastes, assim como a massa seca da parte aérea e da raiz, aumentaram acentuadamente até a lâmina de 73,09 mm, com tendência a estabilização a partir desse ponto, e posterior queda a partir de 104,03 mm. A relação entre a massa seca da parte aérea e a massa seca da raiz demonstrou estresse hídrico severo na lâmina de 11,20 mm, sendo mais danoso ao crescimento das raízes. A altura das plantas apresentou comportamento linear positivo à medida que se aumentou a lâmina, ao contrário da eficiência do uso da água. Portanto, a lâmina com reposição de 50% da ETo, (73,09 mm), proporciona um crescimento inicial adequado para mandioca