Infuence of kaolin application on most important fruit and leaf characteristics of two apple cultivars under sustained defcit irrigation

BACKGROUND: Apple is one of the oldest and most valuable fruits. Water restriction is one of the major problems in the production of this fruit in some planting areas. METHODS: Effects of kaolin spray treatments were studied on two early apple cultivars of Golab and Shafi-Abadi under sustained deficit irrigation (SDI) in Alborz province, Iran during 2017 and 2018. Irrigation treatments were 100%, 85%, and 70% ETc and kaolin application were concentrations of 0, 3 and 6% in 2017 and 0, 1.5 and 3% in 2018. RESULTS: Results showed that 85% ETc treatment compared to other irrigation treatments improved apple tree crown volume in 2017. Deficit irrigation treatments significantly reduced fruit weight in both years. Application with 6% kaolin resulted in 33.3% increase in apple fruit weight compared to non-kaolin treatment at 100% ETc irrigation in the first year. Severe deficit irrigation (70% ETc) significantly reduced apple fruit length in both years, but 6% kaolin increased fruit length in both apple cultivars in 2017. Severe deficit irrigation treatment increased the firmness of apple fruit compared to control and mild deficit irrigation (85% ETc) in the first year of experiment. There was no significant difference between irrigation treatments for apple fruit firmness in the second year of experiment. Kaolin treatments of 1.5% and 3% at full irrigation increased the soluble solids content of apple fruit by 36.6% and 44.1% in 2018, respectively. Deficit irrigation treatments significantly increased leaf proline content compared to control in both years. In the first year, kaolin treatments increased leaf proline but in the second year, leaf proline was not significant. Deficit irrigation treatment of 70% ETc and 6% kaolin had the highest amount of glycine betaine content, malondialdehyde and hydrogen peroxide in apple leaf in the first year of experiment. CONCLUSIONS: Severe deficit irrigation stress (70% ETc) increased the activity of nonenzymatic defense systems of apple trees. Kaolin as a drought stress reducing agent can be recommended in apple orchards of Golab and Shafi-Abadi cultivars as an effective and inexpensive method to improve tolerance to drought stress conditions.

Effects of deficit irrigation and kaolin application on vegetative growth and fruit traits of two early ripening apple cultivars

BACKGROUND: Drought is one of the main serious problems for agriculture production which its intensity is increasing in many parts of the world, hence, improving water use efficiency is a main goal for sustainable agriculture. RESULTS: Growth indices including relative shoot length growth (SL), relative stem diameter increase (SD) and relative trunk cross sectional area growth (TCSA) measured at the start and end of the season decreased by reducing the irrigation level. Chlorophyll index (CI) was decreased at 70% crop evapotranspiration, however water use efficiency (WUE), leaf and fruit total phenolic content (TPC), and fruit anthocyanin content (AC) were among the traits that showed increment by water deficit stress in both cultivars. Shafi-Abadi cultivar showed to be more sensitive to the water stress than 'Golab' Kaolin treatment improved SL, SD and CI traits, but this increase was statistically significant only for SD at 5% level. Kaolin had no significant effect on yield and water use efficiency (WUE), however, it had negative effect on yield efficiency (YE). Kaolin treatments also significantly increased fruit and leaf TPC (P< 0.01) but had no effect on leaf and fruit total antioxidant activity (AA), as well as fruit anthocyanin content (AC) and soluble proteins (SP). CONCLUSIONS: Irrigation at 85% ETc showed better results than 100% and 70% ETc levels for yield attributes. It seems that the more pronounced effect of kaolin on vegetative traits but not on the fruits, might be attributed to the early ripening and harvest time of the examined cultivars.

Exogenous niacin treatment increases NADPH oxidase in kiwifruit / O tratamento com niacina exógena NADPH oxidase em kiwis

Abstract Kiwifruit are a popular fruit worldwide; however, plant growth is threatened by abiotic stresses such as drought and high temperatures. Niacin treatment in plants has been shown to increase NADPH levels, thus enhancing abiotic stresses tolerance. Here, we evaluate the effect of niacin solution spray treatment on NADPH levels in the kiwifruit cultivars Hayward and Xuxiang. We found that spray treatment with niacin solution promoted NADPH and NADP+ levels and decreased both O2·- production and H2O2 contents in leaves during a short period. In fruit, NADPH contents increased during early development, but decreased later. However, no effect on NADP+ levels has been observed throughout fruit development. In summary, this report suggests that niacin may be used to increase NADPH oxidases, thus increasing stress-tolerance in kiwifruit during encounter of short-term stressful conditions.

Resumo Kiwis são uma fruta popular em todo o mundo; No entanto, o crescimento das plantas é ameaçado por estresses abióticos como a seca e as altas temperaturas. O tratamento com niacina em plantas mostrou aumentar os níveis de NADPH, aumentando assim a tolerância a stress abiótico. Aqui, avaliamos o efeito do tratamento com spray de solução de niacina sobre os níveis de NADPH nos cultivares de kiwis Hayward e Xuxiang. Descobrimos que o tratamento por spray com solução de niacina promoveu níveis de NADPH e NADP + e diminuiu a produção de O2·- e os teores de H2O2 nas folhas durante um curto período. Nos frutos, os teores de NADPH aumentaram durante o desenvolvimento precoce, mas diminuíram mais tarde. No entanto, não se observou qualquer efeito nos níveis de NADP + ao longo do desenvolvimento do fruto. Em resumo, este relatório sugere que a niacina pode ser utilizada para aumentar NADPH oxidases, aumentando assim a tolerância ao estresse em kiwis durante o encontro de condições estressantes de curto prazo.

Impact of air pollution on floral morphology of Cassia siamea Lamk.

Cassia siamea plants growing at two different sites (polluted and non-polluted) on two important roads of Agra city exhibited significant differences in their flowering phenology and floral morphology. The flowering in plants growing at polluted site is delayed and there was a marked reduction in flowering density, flowering period, size of floral parts, pollen fertility, fruit and seed-set. SEM observations revealed the presence of well developed glandular structures and reduction in the number and size of large stomata on the anther surface at polluted site. These changes were found to be closely associated with the extent of air pollution caused mainly by significant in the number of automobiles.

Successful propagation in vitro of apple rootstock MM106 and influence of phloroglucinol.

Successful in vitro propagation of clonal apple rootstock MM106 was achieved by culturing axillary buds on MS basal medium with BAP (1 mg/L), GA3 (0.5 mg/L) and IBA (0.1 mg/L). Use of liquid medium (LM) in initial cultures reduced phenol exudation to a greater extent and gave maximum sprouting percentage when transferred to solid MS medium. Phloroglucinol (PG) did not enhance sprouting of buds but increased the rate of multiplication when added in the medium. Maximum number of shoots were obtained when MS medium was supplemented with BAP (0.5 mg/L), GA3 (1 mg/L), IBA (0.1 mg/L) and PG (100 mg/L). For rooting, in vitro regenerated shoots were placed in IBA (30 mg/L) for 3 hr and transferred to solidified auxin free medium. Rooting was recorded in about 80% of shoots. Inclusion of PG in rooting medium was not beneficial but shoot cultures grown in its presence gave higher rooting percentage. Rooted plantlets showed about 70% survival rate in potting mixture of sand:soil:perlite (1:1:1).

Fisiologia pós-colheita do amadurecimento do maracujá-amarelo (Passiflora edulis f. flavicarpa Degener) / Postharvest phyysiology of yellow passion fruit (Passiflora edulis f. flavicarpa Degener) ripening

Com o objetivo de estabelecer relaçöes entre a maturaçäo pós-colheita e o estádio de desenvolvimento do maracujá-amarelo (Passiflora edulis f. flavicarpa) por ocasiäo da colheita, estudaram-se as modificaçöes em alguns constituintes químicos, físicos e na biossíntese do etileno e o efeito do tratamento com ethephon sobre o amadurecimento pós-colheita. A taxa de respiraçäo do fruto mantido na planta decresce gradualmente com o tempo mas sem mostrar o climatério respiratório. A produçäo de etileno e o climatério säo antecipados com a colheita dos frutos. Os frutos colhidos aos 65 dias após a antese apresentam elevaçäo no teor de ACC, na atividade ACC oxidase e na taxa de produçäo de etileno, indicando início da autocatálise. A aplicaçäo de ethephon, imediatamente após a colheita, näo antecipa o climatério respiratório dos frutos, mas aumenta as taxas de respiraçäo, de produçäo de etileno e de perda de massa, bem como, os sólidos solúveis totais e a acidez total titulável. Ao final do amadurecimento, o teor de sacarose aumenta e os de glicose e frutose pouco säo alterados. Os sólidos solúveis se estabilizam, enquanto a acidez total titulável aumenta, até sessenta dias após a antese e entäo decresce. Os resultados indicam que o maracujá-amarelo atinge a maturidade fisiológica entre 60 e 65 dias após a antese

Estudio químico bromatológico de los frutos myrciaria dubia HBK (camu camu) y paraqueiba sericea TUL (Umari) / Chemical bromatologic study of myrciaria fruits dubia HBK (camu camu) and paraqueiba sericea TUL (Umari)

El camu camu es un arbusto que crece a orillas de rios y lagos en Loreto y Ucayali, cuyo fruto de sabor ácido agradable se caracteriza por su alto contenido en vitamina C. El umari es un árbol casi exclusivo del Departamento de Loreto cuyo fruto comestible se caracteriza principalmente por su alto contenido de aceite. Se usaron los métodos de Lane y Eynon y espectrofotometría, para determinar los diversos componentes que serán útiles en su aplicación industrial.