Specific resistance to powdery mildew of wheat (Triticum aestivum L.), incited by Erysiphe graminis f. sp. tritici, has been associated with several major genes that are relatively easy to select in segregating populations. Nonspecific resistance is more difficult to select because of genetic and nongenetic factors that lower heritability. The objectives of this study were to: (i) determine the effectiveness of recurrent selection for accumulating genes for nonspecific resistance to powdery mildew in two winter wheat populations, and (ii) examine the effect of changes in the level of resistance on other components of resistance. Two winter wheat populations (designated Early and Elite) carrying a dominant male sterile gene were subjected to two cycles of recurrent selection for powdery mildew resistance using phenotypic recurrent selection and modified half‐sib family selection. Ten‐day‐old seedlings were inoculated in the greenhouse with a spore suspension consisting of equal amounts of four isolates possessing combined virulence that overcame all known powdery mildew resistance genes except Pm3b and Pm8. Beginning 7 d after inoculation, area under the disease progress carve (AUDPC) was determined four times at 4‐d intervals and used select individuals for the next cycle. The mean AUDPC on the primary leaves of S1 families and the realized gains after two cycles of selection indicated that the Elite population averaged 46% gain over the two selection methods compared to 35% gain for the Early population. Over two cycles, half sib selection gains of 40 and 53% were realized in the Early and Elite population, respectively, while phenotypic recurrent selection reduced AUDPC 30% in the Early population and 40% in the Elite population. For both populations, selection for low AUDPC resulted in significantly decreased final disease severity ratings, colony number, and cumulative sporulation capacity. Duration of the incubation period was significantly increased only with two cycles of half‐sib selection for AUDPC. A high correlation between AUDPC and the final disease severity rating indicated that the breeder could select for nonspecific resistance using a final disease severity rating provided the test materials are all inoculated simultaneously.
Leishmaniasis is one of the most neglected tropical diseases that present areal public health problems worldwide. Chemotherapy has several limitations such as toxic side effects, high costs, frequent relapses, the development of resistance, and the requirement for long-term treatment. Effective vaccines or drugs to prevent or cure the disease are not available yet. Therefore, it is important to dissect antileishmanial molecules that present selective efficacy and tolerable safety. Several studies revealed the antileishmanial activity of medicinal plants. Several organic extracts/essential oils and isolated natural compounds have been tested for their antileishmanial activities. Therefore, the aim of this review is to update and summarize the investigations that have been undertaken on the antileishmanial activity of medicinal plants and natural compounds derived, rom plants from January 2015 to December 2021. In this review, 94 plant species distributed in 39 families have been identified with antileishmanial activities. The leaves were the most commonly used plant part (49.5%) followed by stem bark, root, and whole plant (21.9%, 6.6%, and 5.4%, respectively). Other plant parts contributed less (<5%). The activity was reported against amastigotes and/or promastigotes of different species (L. infantum, L. tropica, L. major, L. amazonensis, L. aethiopica, L. donovani, L. braziliensis, L. panamensis, L. guyanensis, and L. mexicana). Most studies (84.2%) were carried out in vitro, and the others (15.8%) were performed in vivo. The IC50 values of 103 plant extracts determined in vitro were in a range of 0.88 µg/mL (polar fraction of dichloromethane extract of Boswellia serrata) to 98 µg/mL (petroleum ether extract of Murraya koenigii). Among the 15 plant extracts studied in vivo, the hydroalcoholic leaf extract of Solanum havanense reduced parasites by 93.6% in cutaneous leishmaniasis. Voacamine extracted from Tabernaemontana divaricata reduced hepatic parasitism by ≈30 times and splenic parasitism by ≈15 times in visceral leishmaniasis. Regarding cytotoxicity, 32.4% of the tested plant extracts against various Leishmania species have a selectivity index higher than 10. For isolated compounds, 49 natural compounds have been reported with anti-Leishmania activities against amastigotes and/or promastigotes of different species (L. infantum, L. major, L. amazonensis, L. donovani and L. braziliensis). The IC50 values were in a range of 0.2 µg/mL (colchicoside against promastigotes of L. major) to 42.4 µg/mL (dehydrodieuginol against promastigotes of L. amazonensis). In conclusion, there are numerous medicinal plants and natural compounds with strong effects (IC50 < 100 µg/mL) against different Leishmania species under in vitro and in vivo conditions with good selectivity indices (SI > 10). These plants and compounds may be promising sources for the development of new drugs against leishmaniasis and should be investigated in randomized clinical trials.
In the present study, a field experiment was conducted for two consecutive seasons (2016/2017 and 2017/2018). The effects of organic and inorganic fertilization on growth, seed yield, seed fixed oil yield, and fatty acid profile of garden cress (Lepidium sativum L.) were investigated under conditions of Khartoum State, Sudan. In each season, the experiment was laid out in a randomized complete block design with four replications. Four fertilizer treatments were used; these were chicken manure at a rate of 11.9 tonha −1 , NPK (15:15:15) at two rates, 476 kgha −1 (NPK1), 952 kgha −1 (NPK2) as well as the control. Morphometric parameters, yield components, seed fixed oil content (%), seed fixed oil yield (tonha −1), and fatty acids profile were measured. Means were separated using the least significant difference at p ≤ 0.05 and at p ≤ 0.01. The difference between chicken manure, NPK1, and NPK2 was not significant (p ≤ 0.05) in both seasons, for plant height and 1000-seed weight. However, it was significant (p > 0.05) with chicken manure in both seasons for the number of leaves (831.7, 684), the number of branches (144.8, 128.5), fresh weight (57.74, 61.25), and dry weight (6, 7.7). The NPK2 treatment significantly (p ≤ 0.05) increased the number of capsules (339.5, 308 tonha −1), seed yield (5.51, 4.8 tonha −1), seed fixed oil content (25.65%, 25%), and seed fixed oil yield (1.4, 1.1 tonha 1) compared to the control in both seasons. The oil profile was affected by all fertilizer treatments. Acoordingly, it can be concluded that using fertilizer is recommended for improvement of growth, seed yield, and oil yield, and quality of L. sativum.
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