Indian Potato Cultivars Research Articles

Physicochemical, thermal and pasting properties of starches separated from different potato cultivars grown at different locations

The starch separated from 21 different Indian potato cultivars from four locations was evaluated for physicochemical, thermal and pasting properties. The relationships between the different properties of starches were determined using Pearson’s correlation analysis. Amylose content was positively correlated to hot paste viscosity ( r = 0.460, P ⩽ 0.05) and negatively correlated to transmittance measured after storage of 0, 24 and 72 h ( r = −0.509, −0.480, −0.453, P ⩽ 0.05). Hot paste viscosity showed significant positive correlation with cold paste viscosity, pasting temperature, T p and T c ( r = 0.985, 0.607, 0.654, 0.628, P ⩽ 0.005) and negative correlation with transmittance measured after 0, 24 and 72 h ( r = −0.539, −0.570, −0.451, P ⩽ 0.05). Breakdown viscosity showed highly negative correlation with pasting time ( r = −0.766, P ⩽ 0.005) and positive correlation with transmittance measured after 0, 24 and 72 h ( r = 0.533, 0.558, 0.570, P ⩽ 0.05). Pasting temperature showed highly positive correlation with transition temperatures T o, T p, T c ( r = 0.740, 0.846, 0.734, P ⩽ 0.005) and negative correlation with transmittance measured after 0, 24 and 72 h ( r = −0.418, −0.468, −0.476, P ⩽ 0.05). T o showed the highest positive correlation with T p and T c ( r = 0.924, 0.755, P ⩽ 0.005). The results revealed that temperature during tuber growth affects granule size, pasting temperature and transition temperature. Lower temperature prevailed during tubers growth resulted into starch with higher granule size and lower pasting and transition temperatures.

Semi-Automated Simple Sequence Repeat Analysis Reveals Narrow Genetic Base in Indian Potato Cultivars

A study was conducted to generate fingerprints of thirty-two Indian potato cultivars using capillary electrophoresis based semi-automated simple sequence repeat analysis. Five fluorescent-tagged primer pairs (STPOACUTR, LEGAST1, STPOAC58, STM0030 and STM0031) used in this study yielded 43 alleles at 16 different loci, showing multi-loci resolving character. The estimated similarity between the cultivars was in the range of 0.72 to 0.98 indicating narrow genetic relationship. None of the primer set alone could differentiate all 32 cultivars included in this study. However, two primer sets STM-0031 and STPOAC58 amplifying 12 and 9 polymorphic alleles, respectively, could together distinguish all of them. The results indicated usefulness of semi-automated capillary electrophoresis in quick and reproducible SSR genotyping of potato cultivars.

Relationships between various physicochemical, thermal and rheological properties of starches separated from different potato cultivars

AbstractVarious physicochemical, thermal and rheological properties of starches separated from Indian potato cultivars were related to each other using the Pearson correlation. Amylose content, water‐binding capacity (WBC), swelling power, solubility, ash content, transmittance, syneresis and consistency coefficient (K) were determined. Amylose content was significantly correlated with swelling power (r = 0.904), transmittance (r = 0.656) and syneresis (r = 0.777) of the starches. Thermal properties such as transition temperatures (To, Tp and Tc), gelatinisation range (R), gelatinisation enthalpy (ΔHgel) and peak height index (PHI) of the starches were measured using differential scanning calorimetry (DSC). To, Tp and Tc were positively correlated with swelling power and negatively correlated with solubility and WBC. PHI was positively correlated with WBC and negatively correlated with ash content and swelling power. R had a negative correlation with WBC (r = −0.726) and PHI (r = −0.737). A positive correlation between R and Tc was observed. WBC was negatively correlated with swelling power (r = −0.749). Syneresis of potato starches was positively correlated with transmittance, ash content, swelling power and amylose content. K was positively correlated with amylose content (r = 0.587). The results showed a significant variation in various functional and thermal properties of starches separated from different potato cultivars. Copyright © 2004 Society of Chemical Industry

Genetic diversity of late blight resistant and susceptible Indian potato cultivars revealed by RAPD markers

Twenty-four tetraploid Indian potato cultivars were characterized by using RAPD markers to assess diversity within and between late blight resistant and susceptible cultivars. Sixty-four random decamer primers generated802 fragments, ranging in size from 60–3200 bp, with 96.4% fragment polymorphism. Shannon's index of diversity was used to quantify the degree of variability present within and between the variety types. Most of the diversity was detected within variety types, with 88% of variation being within and 12% being between the resistant and susceptible cultivars. No clear groupings based on late blight resistance and susceptibility or kinship was reflected on the dendogram. The late blight resistant cultivars exhibited higher variability compared to susceptible cultivars and they were more dispersed on the PCO plot.

Fingerprinting Indian potato cultivars by random amplified polymorphic DNA (RAPD) markers

Random amplified polymorphic DNA markers were used to distinguish and characterize 20 Indian potato cultivars. A total of 198 scorable fragments were amplified using 10 random primers, only two of which were monomorphic. Similarity values among the cultivars ranged from 0.33 to 0.80. A primer having resolving power above 7.4 was sufficient to distinguish all 20 cultivars. Wide variations in band profiles were observed when the same template DNA was amplified using Taq DNA polymerase from four different sources. No significant difference in profile complexity was observed at 40°C annealing temperature with a primer having 70% GC content. Prior restriction of template DNA resulted in band profiles whose complexity was similar to or higher than that of unrestricted template. However, multiplex RAPD with cleaved template DNA could not increase fingerprint complexity.

Studies on the morphological, thermal and rheological properties of starch separated from some Indian potato cultivars

Abstract The starches separated from five different Indian potato cultivars (Kufri Chandermukhi, Kufri Badshah, Kufri Jyoti, Kufri Sindhuri and S1) were investigated for morphological, thermal, rheological, turbidity and water-binding properties. The starch separated from all the five potato cultivars had a granule size ranging between 15–20 μm and 20–45 μm. The shape of starch granules varied from oval to irregular or cuboidal. Starch isolated from cv. Kufri Badshah had largest irregular or cubiodal granules while starch from cv. Kufri Chandermukhi had small and oval granules. The transition temperatures and enthalpy of gelatinization (ΔHgel) were determined using differential scanning calorimetry (DSC). The enthalpy of retrogradation (ΔHret) of gelatinized starch was also determined after 14 days of storage at 4°C using DSC. Kufri Chandermukhi starch showed the lowest ΔHgel and ΔHret while Kufri Badshah starch showed the highest values. ΔHgel and ΔHret values of 12.55 J/g and 6.42J/g, respectively, for Kufri Chandermukhi starch against 13.85 J/g and 8.61 J/g, respectively, for Kufri Bhadshah starch were observed. Rheological properties of starches from different potato cultivars, measured using the Dynamic Rheometer during heating and cooling, also differed significantly. The starch from cv. Kufri Badshah showed the highest peak G′ and G″ and lowest tan δ. The starches having higher peak G′(G′ at gelatinization temperature) showed higher breakdown in G′ and vice versa. The turbidity of gelatinized aqueous starch suspensions from all potato cultivars increased with increase in storage period. Starches with low water binding capacity had higher G′ and G″ and lower tan δ values.

Field resistance to late blight of four indian potato cultivars

The nature and extent of field resistance to late blight, and the effect of plant age and inoculum level on resistance components and host attributes, were studied on the Indian potato cultivars Kufri Chandramukhi, Kufri Jyoti, Kufri Badshah and Kufri Sherpa. Latent period, infection efficiency, colonization rate and sporulation were found to operate in cvs Kufri Jyoti, and Kufri Badshah. Based on component analysis cv. Kufri Jyoti was similar to or sometimes more resistant than Kufri Badshah. No correlation was observed between any of the host attributes and resistance to late blight, except that the erect canopy of Kufri Badshah was associated with its slow blighting rate. At high inoculum, colonization rate and total sporulation were increased but infection efficiency was decreased.

Effects of gamma irradiation and temperature on sugar and vitamin C changes in five Indian potato cultivars during storage

The changes in sugar and vitamin C content of five potato cultivars subjected to gamma irradiation (100 Gy) to cause sprout inhibition were compared with nonirradiated control tubers during storage at 27–32°C (ambient temperature) and 15°C, and also with control tubers stored at 2–4°C—the commercial cold storage temperature. Reducing and nonreducing sugars increased during extended storage at all temperatures, the maximum increase occurring at 2–4°C. The proportion of nonreducing sugars was higher at 27–32°C, whereas at 2–4°C reducing sugars formed the greater proportion. Irradiation did not influence the pattern of sugar accumulation. Irradiated potatoes stored at 15°C for 6 months had lower sugar levels than control tubers stored at 2–4°C. During the first 2 months vitamin C levels were lower in irradiated potatoes stored at 15°C than in the controls stored at 2–4°C, but were subsequently higher. The suitability of tubers for processing into crisps and french fries was not affected by irradiation and storage at 15°C for 6 months.

Storage deterioration in gamma-irradiated and unirradiated Indian potato cultivars under refrigeration and tropical temperatures

Experiments with ten potato varieties revealed that soft rot due toErwinia carotovora var.atroseptica is the major factor causing 30 to 70% losses during 2 to 4 months storage at tropical temperatures (27 32 C). Sodium hypochlorite wash or increased ventilation did not reduce the incidence of soft rot. Storage at 10–15 C markedly reduces soft rot but accelerates sprouting.