Photoperiod is one of the most important maternal factors with an impact on the offspring diapause induction of Locusta migratoria. Previous studies have shown that forkhead box protein O (FOXO) plays an important role in regulating insect diapause, but how photoperiod stimulates maternal migratory locusts to regulate the next generation of egg diapause through the FOXO signaling pathway still needs to be addressed. In this study, the transcriptomes of ovaries and fat bodies of adult locusts under a long and short photoperiod were obtained. Among the total of 137 differentially expressed genes (DEGs) in both ovaries and fat bodies, 71 DEGs involved in FOXO signaling pathways might be closely related to diapause induction. 24 key DEGs were selected and their expression profiles were confirmed to be consistent with the transcriptome results using qRT-PCR. RNA interference was then performed to verify the function of retinoic acid induced protein gene (rai1) and foxo. Egg diapause rates were significantly increased by RNAi maternal locusts rai1 gene under short photoperiods. However, the egg diapause rates were significantly decreased by knock down of the foxo gene in the maternal locusts under a short photoperiod. In addition, reactive oxygen species (ROS) and superoxide dismutase (SOD) activities were promoted by RNAi rai1. We identified the candidate genes related to the FOXO pathway, and verified the diapause regulation function of rai1 and foxo under a short photoperiod only. In the future, the researchers can work in the area to explore other factors and genes that can promote diapause induction under a long photoperiod.

Egg diapause in Locusta migratoria L. (Orthoptera: Acridoidea) is believed to be influenced by maternal photoperiod. However, the molecular mechanism regulating the phenomenon of maternal diapause induction is unclear. Here we performed transcriptomic analyses from the central nervous system (CNS) of migratory locusts under long and short photoperiods to identify differentially expressed genes (DEGs) related to diapause induction. There were total of 165750 unigenes from 569491 transcripts, and 610 DEGs were obtained in S_CNS (CNS of short photoperiod treated locusts) vs. L_CNS (CNS of long photoperiod treated locusts). Of these, 360 were up-regulated, 250 were down-regulated, and 84 DEGs were found to be related to FOXO signaling pathways, including citrate cycle/TCA cycle, glycolysis/ gluconeogenesis, oxidative phosphorylation, and PI3K-Akt. The qRT-PCR validation of mRNA expression of 12 randomly selected DEGs showed consistency with transcriptome analysis. Furthermore, the takeout gene thought to be involved in circadian rhythm was cloned and used for RNAi to observe its function in maternal diapause induction. We found that the mRNA level of Lm-takeout was significantly lower in dstakeout treatments as compared to the control under both long and short photoperiods. Similarly, the offspring diapause rate was significantly higher in dstakeout treatment as compared to the control only in short photoperiod. This shows that the Lm-takeout gene might be involved in the inhibition of maternal diapause induction of L. migratoria under short photoperiods. The present study provides extensive data of the CNS transcriptome and particular insights into the molecular mechanisms of maternal effects on egg diapause of L. migratoria. As well for the future, the researchers can explore other factors and genes that may promote diapause in insect species.

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Diapause is an important overwintering strategy enabling Locusta migratoria to survive under stressed conditions. We identified a novel dual‐specificity kinase gene that is differentially expressed between long and short day‐treated L. migratoria. To determine its function on photoperiodic diapause induction, we cloned the specific gene. Interestingly, phylogenetic analysis shows that this dual‐specificity kinase is of the mycetozoa protein kinase‐like (MPKL) type and may have been transferred horizontally from Mycetozoa to L. migratoria. RNA interference results confirm that MPKL promotes photoperiodic diapause induction of L. migratoria. Furthermore, MPKL significantly inhibits Akt and FOXO (i.e. forkhead box protein O) phosphorylation levels in ovaries, and also enhances reactive oxygen species, superoxide dismutase and catalase activities, whereas peroxidase activity is decreased under both photoperiodic regimes. The findings of the present study offer insight into the molecular mechanism responsible for dual‐specificity kinase‐induced diapause in insects.

Okra (Abelmoschus esculentus L.) can contract okra yellow vein mosaic disease (OYVMD) caused by Bhendi yellow vein mosaic virus (genus: Begomovirus and family: Geminiviridae), vectored by whitefly (Bemisia tabaci). This study was carried out to screen okra varieties for resistance to OYVMD and to determine the correlation of vector population with the severity of the disease. Six varieties namely, Tulsi, Durgah, Sabz Pari, Sarahariya, Ramaan Kirshna and Pooja were grown under field conditions at localities of Shahpur, Tando Adam and Peer Kathi during rabi (winter cropping) and kharif (summer cropping) seasons during 2016 and 2017, respectively. The first incidence percent of the disease was recorded in the 8th week during rabi and the 6th week during kharif growing season. The Tulsi variety remained disease-free during both growing seasons. A significantly lower disease incidence % was recorded in Sabz Pari (29.32%) and Sarahariya (30.09%) varieties than Durgah, Ramaan Kirshna and Pooja during the rabi growing season. Both varieties were disease-free during the kharif season. There was remarkable variation in disease severity recorded in okra varieties at different trials during rabi and kharif seasons using a 0-6 rating scale (i.e., 0 = The disease-free plants, 1 = 1-10 % vein clearing, 2 = 11-25 % vein yellowing of small leaves , 3 = 26-50 % yellow network on some leaves, 4 = 51-60 % yellow network on all leaves, 5 = 60-70 % complete leaves turn yellow or cream color and 6 = 70 % plant stunted, deformed and small fruit and whole plants becomes colorless). Whitefly appeared in the 5th week during the rabi and 4th week during the kharif growing seasons. Vector population during the rabi growing season was significantly higher than in the kharif season. There was a nonsignificant relationship between disease severity and whitefly population in Ramaan Kirshna, Sarahariya, and Sabz Pari varieties. The disease severity in the Pooja variety showed a significant relationship with vector population, but only in the Tando Adam trial (R2= 0.7455, P= 0.0084), whereas the Durgah variety showed a significant relationship between disease severity and vector population in Shahpur (R2= 0.6615, P= 0.0267) and Tando Adam trials (R2= 0.8235, P= 0.0018). The same variety showed a nonsignificant relationship between disease severity and vector population in the Peer Kathi trial. It is concluded that Sabz Pari and Tulsi varieties are resistant to the disease

T omato (Lycopersicume esculentum Mill.) belongs to the family Solanaceae and is a popular grown vegetable and rank third of worldwide vegetable production (Sadaf et al., 2012). Tomato is a good source of vitamins (A and C) and minerals. It is one of the most widely grown vegetable crops, highly popular due to its high nutritive value, taste and versatile use in various foods. In Pakistan tomato crop is cultivated on 58.4 thousand hectares, with production of 551.0 thousand tonnes and per hectare yield is estimated Abstract | Tomato (Lycopersicum esculentum Mill.) is important vegetable in Pakistan. Tomato leaf curl viral disease caused by tomato leaf curl virus (TLCV) (genus: Begomovirus, family: Geminiviridae) and transmitted by whitefly (Bemisia tabaci) is considered as the most devastating one. Recently, available tomato varieties are not screened against this disease in the agro-ecosystem of Sindh Province of Pakistan. Therefore, in this study 12 commercial varieties of tomato such as, TO

Cucumber mosaic virus (Genus: Cucumovirus, Family: Bromoviridae) is major pathogen of cucumber (Cucumis sativus L.) in Pakistan and may cause up to 100 % losses. Therefore, this survey based study was planned to determine the disease intensity in fields, mechanical transmission for confirmation of virus and analysis of influence of environmental conditions on the disease development. The disease was monitored on 30 plants at each site in district Hyderabad, Tando Allahyar, Thatta and Shaheed Benazirabad. There were seven sites at each district for observations. Metrological data collected from Regional Agro Metrological Centre, ARI Tandojam Sindh was correlated with the disease intensity. The disease incidence was ranging, 40-77, 37-70, 63-100 and 30-90%, at district Hyderabad, Tando Allahyar, Thatta and Shaheed Benazirabad, respectively. District wise, there was highly significant variation among incidence of cucumber mosaic disease (Df= 3, F= 20.59, P= 0.0000). Maximum disease incidence was recorded at Thatta (81.0%). However, overall severity of cucumber mosaic in all the surveyed districts was 2-score. On mechanical inoculation, after 15 days necrotic lesions were only found on the leaves of Chenopodium amaranticolor inoculated with sap of symptomatic leaves. Maximum, minimum temperature (℃) and evaporation showed significant relation (r 2 = 0.883, P= 0.0053, r 2 = 0.664, P= 0.0482 and r 2 = 0.827, P= 0.0119, respectively) only with the disease incidence but not with severity. Cloudiness was highly significantly related with disease severity (r 2 = 0.975, P= 0.0002) but there was non-significant relationship with disease incidence (r 2 = 0.600, P= 0.0705).