Breeding Lines Influence on Growth, Yield and Quality Characteristics of Cutleaf Groundcherry (Physalis angulata L.)

Experimental site and design
 
The pot experiment was conducted in the Experimental Garden of Faculty of Agriculture, Universitas Brawijaya, located in Lowokwaru district, Malang, East Java, Indonesia, situated at altitude of 440-460 m above sea level, the temperature 23.3°-27.1°C, air humidity 50-80%. In this study was used a randomized block design, consisting of nine lines of cutleaf groundcherry (PA01-PA09) with three replications. Each treatment consisted of 15 polybags, the total was 405 polybags. P. angulata lines used were the result of selection where the lines have the potential to be developed as fruit or medicinal plants. The seeds were sown in nursery trays in a 1:1:1 mixture of soil, sand and cow manure. The seedlings were transplanted 21 days after sowing in a polybag mixture of soil and cow manure (with dose 40 t ha^-1). Characteristics the planting media were: pH 5.9-6.0; C-organic 1.83%; N-total 0.21%.
 
Maintenance
 
Standard agronomic practices were used to grow the cutleaf groundcherry seedlings. Fertilization was carried out at 7 and 21 day after transplanting, with a dose of 150 kg ha^-1 nitrogen, potassium 100 kg ha^-1 K₂O and phosphorus 60 kg ha^-1 P₂O₅. Phosphorus was applied at planting time, Half dose of potassium and nitrogen were applied 3 days after planting and remaining 1/2 doses at 21 days after planting.  The plants were watered manually with ± 300 ml of groundwater once a day (morning or afternoon). Manual weeding around the plants was performed every five days. Cutleaf groundcherry fruits were harvested when they turned yellow and the calyx dried up.
 
Measurements
 
We measured the growth variable i.e. leaf area, total plant dry weight were recorded at 2, 4, 6, 8, 10 WAP (Weeks after planting) and relative growth rate (RGR). RGR was calculated from equation (Price and Munns, 2018):

 

 
Where,
W= Total dry weight (g Plant^-1).
T= Time of measurement (week).

Yield variable namely: diameter of fruit, fruit weight fruits^-1, fruit fresh weight and the number of fruits plant^-1. The fruit fresh weight plant-1 was noted as the accumulated total from the first to the last harvest.

The fruit quality variable consisted of ascorbic acid, total soluble solids (TSS), β-carotene and antioxidant. Measurement of fruit qualities was carried out at harvest time. TSS was measured using a handheld refractometer. β-carotene in the fruit with a UV-Vis spectrophotometer as described by Arnon et al., (1949). Ascorbic acid in the fruit was determined with the titration method reported by Sudarmaji et al., (1997); antioxidant (DPPH activity) in the fruit by UV-Vis spectrophotometer as given by Gupta et al. (2016).

The analysis of variance with F test at 5% error level used to analysed the data and further with HSD a 5%.

Plant growth
 
Variation in growth was observed among cutleaf groundcherry lines (Fig 1). Plant growth pattern of PA 06 and PA 05 was found better than the other lines in terms of total plant dry weight. In the second week to the sixth week, cutleaf groundcherry experienced a rapid growth phase, while at the age of 8 and 10 WAP growth decreased. This is supported by the highest relative growth rate at 2 to 4 WAP and 4 to 6 WAP (Table 1). In the second to fourth week, there was an increase in biomass starting from 6-8 WAP, there was rather the increase however, the decrease was found in biomass and same was recorded at the age of 8 - 10 WAP. The rapid growth of the cutleaf groundcherry lines from the 2-6 WAP was noted so it may be called as grand growth period, it could be due to the variable leaf area. Leaves has role in the photosynthesis process, wider of the leaves causes plants be able to produce more photosynthates, therefore the total dry weight also increased sharply. On the growth variable (total dry weight, leaf area), were different in each lines. PA 06 and PA 05 had higher total dry weight and leaf area compared to other lines. Similar was reported by Gulubkina et al. (2018) and found growth and yield variable different in cultivar of Physalis angulata, Phaseolus vulgaris (Basavaraja et al., 2021), Physalis peruviana (Sharma et al., 2019), Ipomoea batatas (Reddy et al., 2018).




 
Yield characteristics of cutleaf groundcherry
 
Each line varied in yield characteristics as number of fruits, fruits diameter and fruits weight (Table 2). The numbers of fruit ranged from 33.92-45.58 were observed in PA 06, PA 03 and PA 07 which were higher than other lines. Compared to similar species, the number of fruits could be categorized as low by Golukina et al., (2018) and they reported number of fruits was 47-64 fruits plant^-1. The fruit weight of cutleaf grouncherry was 1.32-1.83 g fruit^-1 however, PA 06 had higher fruit weight and fruit diameter (14.13 mm) more than other lines. Similar reported by Tanam et al. (2019) and noted PA 01-PA 09 produced fruit weight plant^-1 range between 42.22-70.09 g plant^-1. Among nine lines, PA 06 had fruit weight (70.09 g plant^-1) more than other lines. Similar was reported by Leite et al., (2017), fruits weight of Physalis angulata was 38-55 g plant^-1. However, fruits weight plant^-1 of Physalis angulata very low than Physalis peruviana (161.60 g plant^-1) (Gocher et al., 2017).


 
Quality characteristics of cutleaf groundcherry
 
Total soluble solid is defined as sugar and soluble minerals in fruits. Based on the results of measurements, the total soluble sugar content of 7.17-8.200 brix (Table 3). Total soluble solid content was higher than the results of Golubkina et al., (2018) as 4.7-7.8°brix. However, it was lower than total soluble solid of Pysalis pubescens (9.70 Brix) and strawberry 7-10°Brix (Li et al., 2017). β-carotene is the orange pigment in plants such as in fruits, leaves, tubers and flowers (Cseke et al., 2006). β-carotene is the most abundant pro-vitamin A carotenoid, which can be converted to Vitamin A (Amengual, 2019). β-carotene content influenced by genetic and environment factors. The result of experiment shows that β-carotene content of nine lines range from 0.056-0.093 mg g^-1. When compared β-carotene content in Physalis angulata and Physalis peruviana, it was high β-carotene in Physalis peruviana as 26.62 mg kg^-1 (Olszanska et al.,  2017).



Vitamin C or known as ascorbic acid, widely known as potent antioxidant (Bedhiafi et al., 2022). The content of ascorbic acid in the PA 01-PA 09 cutleaf grouncherry lines (Table 3). was 44.00-53.68 mg 100 g^-1. That was higher than the ascorbic acid in tomato i.e. 20-30 mg 100 g^-1 (Akhtar et al.,  2010; Ahmad et al., 2015; Du Yu-dan et al., 2017). It was high in cutleaf groundcherry than muskmelon 7.74 - 13.32 mg 100 g^-1  (Lin et al.,  2004), strawberry 16-27 mg 100 g^-1 (Li et al.,  2017) and Physalis peruviana 9-19 mg 100 g^-1 (Ariati et al., 2017;  Iwansyah et al., 2019). An antioxidant content in PA 01-PA 09 was 56.45-58.70% (Table 3), the consistant results was reported by Yildiz et al., (2015), that was recorded 57-59%.

The nine lines of cutleaf groundcherry were significantly varied in characteristics of growth, yield and quality. On the basic of observation recorded PA 06 had higher vegetative growth and total dry weight and yield. The nine lines had the same as total soluble solids and ascorbic acid, but differences in b-carotene and antioxidant. Based on the results obtained for growth, yield and quality, it can be used as a basis for consideration of the development of lines, either as fruit crops or medicinal plants.

Indonesian Ministry of Education, Culture, Research and Technology, through BPPDN scholarship was funded this research.