Effect of Tomato yellow leaf curl virus (TYLCV) Infection of some Tomato (Solanum lycopersicom L.) Genotypes on Fruits Content of Lycopene and some Vitamins

The response of some genotypes of tomato plant (Solanum lycopersicom L.) to infection with the Tomato yellow leaf curl virus (TYLCV) was tested, and the effect of infection on genotypes (123, Narcan and Summer 21) on the fruit content of vitamins C and E and lycopene was evaluated. The field experiment was carried out in the western orchards of Samawah, Al-Muthanna Governorate, Iraq, and the analysis of vitamins and lycopene was carried out in the laboratories of Ghayat Al-Maarifa Company - Babylon. The genotypes were inoculated with whitefly (Bemisia tabaci) and tested by polymerase chain reaction (PCR). The results showed that all genotypes of tomato plants were sensitive to the virus, with differences in the time of appearance and severity of disease symptoms. The genotypes Nahrayn and Summer 21 were the most severely infected with the virus (96 and 87%, respectively) compared to the rest of the genotypes. The results showed a decrease in the vitamin C and vitamin E content of tomato fruits to 8.84 and 0.403 mg /100 gm, respectively, in virus-infected plants, with a significant difference from their normal levels in uninoculated plants, which resulted in 15.8 and 0.931 mg /100 gm, respectively. It was also observed that infection with the virus had a clear effect and significantly decreased the level of lycopene to 9.79 mg/kg fresh weight compared to 14.12 mg/kg fresh weight in uninfected plants. Regardless of the type of plant, infection with the Tomato yellow leaf curl virus (TYLCV) significantly reduced the average dry weight of shoots and roots of infected plants by 28.89 and 3.15 g/plant, compared to 84.08 and 10.13 g/plant for control plants, respectively. The results also showed a clear effect of the virus in reducing the yield of genotypes, which recorded 409.1 g/plant, with a significant difference from the yield of the same genotypes not infected with the virus, which recorded 1697.3 g/plant.


Introduction
Tomato (Solanum lycopersicom L.) occupies the first place in terms of importance among vegetable crops in most countries of the world, including Iraq.The importance of tomatoes is attributed to the fact that the fruits contain some vitamins such as vitamin A and C, and mineral elements such as iron 1259 (2023) 012092 IOP Publishing doi:10.1088/1755-1315/1259/1/012092 2 and phosphorus, which made them consumed fresh as well as used in many food industries [1].According to the report of the Food and Agriculture Organization, the productivity of tomatoes reached 186.9 million tons worldwide, and the cultivated area is 5.06 million hectares in 2020, and developing countries in Asia contribute more than a third of the total production [2].In Iraq, the local production of tomatoes for the year 2020 was estimated at about 754.8 thousand tons, an increase of 21.8% compared to the production for the previous year, which was estimated at 619.5 thousand tons for a cultivated area estimated at 128 thousand dunums [3].One of the determinants of tomato production is its infection with fungal and viral diseases, the most important of which is Tomato yellow leaf curl virus (TYLCV) [4,5].Tomato yellow leaf curl virus (TYLCV) belongs to the family Geminiviridae which includes 441 species in fourteen genera, including the genus Begomovirus to which the tomato leaf curl virus belongs, These genera differ among themselves in terms of genome organization, types of insect vectors, and evolutionary relationships among them [6].This virus is one of the most widespread viruses in the countries of the world, including Iraq, causing economic losses that may reach 100% in many economic crops, including the tomato crop, which is the main host of the virus [7,8].[9], showed a significant decrease in all vitamins content of Telfairia plants in TeMVinoculated plants compared to uninoculated plants.This study aimed to know the response of some genotypes of tomato plant against the effect of the tomato leaf curl virus (TYLCV), as well as its effect on the content of vitamins C and E, lycopene, dry weight and yield per plant of some tested genotypes.

Isolation of Tomato Yellow Leaf Curl Virus (TYLCV)
Tomato plants showing symptoms of viral infection represented by wrinkled, yellowing, and stunted leaves were collected from tomato cultivation areas in Al-Muthanna Governorate during the 2020-2021 growing season.Infected plants were transplanted in plastic containers (22×24 cm) and maintained in a plastic house in a private farm in Al-Muthanna Governorate.The plants were placed in wooden cages (50 x 50 x 60 cm) with a wooden base covered with tulle fabric.Newly grown uninfected tomato plants (4-6 true leaves) were placed in the same boxes every 2-3 weeks for maintaining virus transfer by whiteflies (Bemisia tabaci) and keeping the source of the virus.

Diagnosis of TYLCV using PCR
The TYLCV's DNA was extracted from the leaves of infected plants using the kit.Carry out the GO TAQ® G2 Green Mix preparation by the American company PROMEGA and the total size of 25 microliters containing one microliter of all the front sentence (GAATTCATCTCAGCAGCWCCA, GAATTCATGTCGAAGCGWCCA) And one microliter of DNA (30 nanogram/microliter).All ingredients required to interact in the (PCR Tube) and the volume was completed to 25 microliters with Nuclease-Free Sterile Distilled Water.The DNA was doubled to the virus isolation under study using the steps and conditions of serial polymery interaction (PCR) used by [10].

2.3.
Response of some Tomato Genotypes to TYLCV Infection 14 genotypes of tomatoes have been tested to determine the extent of their response to a virus (Tomato yellow leaf curl virus) (Table 1).Seeds of each genotype were planted separately in planting cork dishes that contain soil and peat moss.The seedlings were then transplanted in Plastic pots (8 x 13 cm) for use in subsequent experiments.Plants at age of 2-3 real leave were inoculated with virus using viruliferous whiteflies.After 48 hours of virus inoculation, the plants were sprayed with Mospilan SL (Acetamiprid 20%) and transferred to a plastic house sealed with tulle cloth to prevent insects from entering.The control plants of each tomato genotype were inoculated using non-viruliferous white fly insects.Control plants were also isolated in a separate plastic house with the same restrictions.The plants were monitored on a daily basis to record the emergence and development of disease symptoms.The presence of the virus was detected by extracting DNA from inoculated plants and tested by polymerase chain reaction (PCR).

Effect of TYLCV Infection on Fruits Content of Vitamin E and C
The vitamin content in tomato fruits was estimated using the method mentioned by [11].The method of [12] was used to measure vitamin E. As for the lycopene content of tomato fruits, the method of [13] was used.

Yield Measures
At the end of the season, the plants were uprooted with the help of running water to facilitate the process of extracting the plant and cleaning the dust attached to the root.The fresh weight of each plant was recorded, then the plant (replicate) was placed in a paper bag and left to air-dry until the weight was fixed and the dry weight was recorded.The biological yield (vegetative and root) (g/plant) and the yield of a plant (g/plant) were estimated using the following equation [14]: Plant yield (g) =(yield of the experimental unit (g))/(number of plants in the experimental unit) The percentage of reduction was also measured for each treatment.
% decrease=(Value of uninfected plants -Value of infected plants )/(Value of uninfected plants)

Experimental Design and Statistical Analysis
This field experiment was carried out with four replications as a Randomized complete Block design (RCBD).The data were analyzed statistically using Genstat statistical analysis software.The means were compared using the Least Significant Difference (L.S.D) test at a probability level of 0.05.

The Severity of Infection
The results of testing the response of some genotypes of tomato plants against TYLCV showed that all genotypes were sensitive to infection with the virus and showed a difference in the time of appearance and severity of the resulting disease symptoms (Table 2).The highest infection severity of 96% was in the Nahrayn genotype, which was not significantly different from the Summer 21 genotype with an infection severity of 87%, while the genotype 123 showed the lowest infection severity of 40%, which differed significantly from all other genotypes.The genotypes of Super regina, Marina, Miami, Sata, Navya, Rochstar, Maysaloun, Madena, Nacran, Samar and Bdoor showed infection strains ranging from 56-80% (Fig. 1).The early disease symptoms appeared on genotypes Nahrayn and Summer 21 with higher infection severity.After that, the infection spread rapidly to the lower leaves at 15 days post inoculation with the virus, which later developed into severe curling and wrinkling of the upper leaves with dwarfing of the plant and falling flowers.
The results of the study agreed with many researchers about the sensitivity of many different genotypes of tomato to infection with TYLCV‫و‬ with reference to the difference in genotypes in the severity of infection [15][16] [17].Tomato genotypes that showed the lowest severity of infection 123, medium infection Narcan, and the highest affected Summer 21 by infection were selected among the genotypes under study to study the effect of infection with TYLCV on the characteristics of the fruits and yield under study.

Effect of Infection with (TYLCV) in Different Tomato Genotypes on Fruit Content of Vitamins C and E According to the Vitamin C Content of Tomato Fruits
The results showed a clear decrease in the tomato content of vitamin C in plants infected with (TYLCV) (Figure2).3) that TYLCV had a clear effect on the content of vitamin E in tomato fruits, which recorded a level of 0.403 mg/100 g. which significantly differed from that of uninfected fruits recording 0.931 mg/100 g.Genotypes 123, Narcan, and Summer 21 showed a clear difference in their vitamin E content, as the highest value was in genotype 123 (0.744 mg/100 g), which differed from the genotypes Narcan and Summer 21 that recorded rates of 0.642 and 0.615 mg/100 g, respectively.Similar to the effect of infection on the concentration of vitamin C, Summer 21 infected with the virus had the lowest content of vitamin E (0.306 mg/100g), which differed significantly from the content of plants not infected with the virus, which gave an average of 0.924 mg/100g.The results also showed that the highest level of vitamin concentration was at genotype 123, which recorded (0.521 mg/100 gm), significantly different from the value of 0.967 mg/100 gm in uninfected plants.The rates of decrease in the vitamin E level were also compared between genotypes, as 123 recorded the lowest percentage of decrease, reaching 46.14%, compared to the highest percentage of decrease in the genotype Summer 21, which recorded 66.92% (Fig. 4).Table 3.Effect of infection with TYLCV of some tomato genotypes on the fruit content of vitamin E.  [18], it was found that the concentration of ascorbic acid was significantly reduced in tomato fruits infected with (TYLCV).On the other hand, [9] indicated that a clear decrease was identified in Telfairia occidentalis fruit content of all vitamins in plants inoculated with Telfairia mosaic virus (TeMV) compared to uninfected plants.

Effect of Infection with TYLCV on the Content of Lycopene Genotypes of Tomato Fruits
The results showed that TYLCV had a clear effect in reducing the level of lycopene (9.79 mg/kg fresh weight) in the fruits of the infected plants, which differed significantly from its level in the uninfected plants, which recorded an average of 14.12 mg/kg fresh weight.Genotype 123 recorded the highest rate of lycopene concentration with a value of 12.66 mg/kg FW, compared to genotype Summer 21, which recorded the lowest rate of 11.43 mg/kg FW (Table 4).The results also showed a significant decrease of lycopene in all genotypes infected with the virus, compared to non-infected plants, the highest rate was in genotype 123 among infected plants compared to the lowest rate recorded in genotype Summer 21.The genotype Summer 21 gave the highest percentage of decrease in lycopene level, 34.62%, compared to genotype 123, which recorded the lowest percentage of decrease of 25.41% (Fig. 2).Table 4. Effect of infection with TYLCV of some tomato genotypes on the fruit content of lycopene.The results of the study agreed with the results of [19] which showed a decrease in the amount of lycopene in tomato fruits infected with TYLCV compared to non-infected plants.[20] also showed that infection of tested genotypes against Tomato mosaic virus (ToMV) affected the plant content of lycopene present in infected tomato fruits with a significant difference from uninfected plants.

Effect of TYLCV on Shoot and Root Dry Weight of Tomato Genotypes Plants Under Study
The genotypes showed clear differences in the average shoot and root dry weights, as the highest value was recorded for genotype 123 (65.42 and 7.36 g/plant, respectively) with a significant difference from the values of the rest genotypes, which was the lowest in the genotype Summer 21 (50.83 and 5.72 g/plant, respectively) (Table 5).The results also showed that the least effect of reducing the dry weights of the vegetative and root groups due to viral infection was in genotype 123 compared to Summer 21, which gave the lowest values of shoot and root dry weights.It is also clear that the highest decrease rates for the shoot and root DW were recorded in the genotypes Summer 21, which amounted to 75.05 and 77.23%, respectively, while 123 showed the lowest rates of decrease, with values of 54.97 and 61.37%, respectively (Fig. 3).Table 5.Effect of TYLCV infection on shoot and root dry weight of tomato genotypes under study.

The Effect of Infection with TYLCV on the Genotypes of Tomato Plants
It is noted from the results (Table 6) that infection with the virus reduced the total genotype yield by a significant difference from the yield of the same uninfected genotypes.It was also found that there are clear differences in yield rates between plants of different genotypes.The highest yield was recorded in genotype 123, which differed significantly from the rates of the yield of plants for the rest of the genotypes, and the lowest yield was recorded in genotype Summer.The same table also shows that genotype 123 was the most tolerant to infection with (TYLCV), as the average plant yield was 723.3 g/plant, and it was significantly different from the single plant yield of the Narcan genotype, which recorded 393.0 g/plant.It was also found that these genotypes were significantly different from the yield of plants of the same genotypes that were not infected with the virus.It was also noted that the lowest rate of yield was recorded in genotype Summer 21 (111.0g/plant).In the case of the decrease percentages among the three genotypes, the Summer 21 genotype gave the highest decrease rate of 93.21%, while genotype 123 recorded the lowest decrease rate with a value of 59.7% (Fig. 4).Infection with TYLCV resulted in a significant decrease in yield for genotypes tested in this study compared to uninfected plants with the same genotypes.This is generally due to the effect of the viral infection on the plant content of mineral elements, plant hormones and enzymes that have a vital role in regulating the physiological processes in the plant.Also, one of the most important reasons that led to the decrease in productivity in infected plants is the decrease in the process of flowering, the formation of florets and inflorescences, the fall of flowers and the failure of fruit formation.Consequently, this led to the plant not forming tomato fruits, and if they did, they would be small in size.In addition, the effect of the virus on plant dry weight [15][16][17][18][19][20][21][22][23].[20] reported that TYLCV infects the phloem cells, causing a decrease in the rates of transport and distribution of nutrients, which leads to a decrease in the level of many materials necessary for building and sustaining plant life.Thus, the effect of infection on the quantity and quality of the resulting fruits.The results also agreed with [15,24,25], who found that infection with (TYLCV) led to a significant reduction in the productivity of several tomato genotypes.[26,27] also found that infection of cucumber and watermelon plants with cucumber mosaic virus (CMV) led to a significant decrease in the productivity of infected plants when compared to healthy plants.

Conclusion
In this experiment, 14 different tomato plant genotypes were investigated for susceptibility to TYLCV, and knowing the effect of the virus on the contents of tomato fruits of vitamins (vitamin E and vitamin C) and lycopene, in addition to knowing the effect of the virus on the dry weight of the plant and the yield of one plant.The virus reduced the contents of infected tomato fruits, including vitamin C and vitamin E, as well as the lycopene content of the fruits, as well as the dry weight of the plant and yield per plant.

Figure 1 .
Figure 1.The severity of infection (%) with TYLCV in tomato genotypes tested in this study.

Figure 2 .
Figure 2. The relationship between infection severity and fruit content decrease of vitamin C, E, and lycopene in tomato genotypes 123, Nakran, and Summer 21 infected with TYLCV.

Figure 3 .
Figure 3.The relationship between infection severity and shoot and root dry weight in tomato genotypes 123, Nakran, and Summer 21 infected with TYLCV.

Figure 4 .
Figure 4.The relationship between infection severity and percentage decrease in yield per plant in tomato genotypes 123, Nakran, and Summer 21 infected with TYLCV.

Table 1 .
Tomato genotypes tested against TYLCV under study.

Table 2 .
The genotypes differed in their fruit content of vitamin C. It was found that the highest level of the vitamin was in genotype 123 (13.75 mg/100g), while genotype Summer 21 recorded the lowest rate of vitamin(11.43 mg/100g).The results showed that the genotype Summer 21 infected with the virus had the lowest vitamin C content, recording 7.01 mg/100, with a significant difference from the vitamin level in the uninoculated plants, which recorded 15.85 mg/100 g.In general, the highest level of vitamin concentration in infected plants was in genotype 123 (10.76 mg/100 gm), which differed significantly from the vitamin value in uninfected fruits with 16.74 mg/100 g of the same genotype.By comparing the rates of decrease in vitamin C concentration, it was found that genotype Summer 21 recorded the highest percentage of reduction of vitamin C (55.74%) while the lowest decrease rate of 35.76% was observed in genotype 123 (Fig.4).Effect of infection with TYLCV of some tomato genotypes on the fruit content of vitamin C.

Mean Vitamin C (mg/ 100 g.) Genotype Non-infected plants Infected plants
In the case of vitamin E, It is clear from the results (Table

Table 6 .
Effect of TYLCV on plant yield of different tomato genotypes under study.