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Acharya N G Ranga Agricultural University, Guntur
The Andhra Pradesh Agricultural University (APAU) was established on 12th June 1964 at Hyderabad.
The University was formally inaugurated on 20th March 1965 by Late Shri. Lal Bahadur Shastri, the then Hon`ble Prime Minister of India. Another significant milestone was the inauguration of the building programme of the university by Late Smt. Indira Gandhi,the then Hon`ble Prime Minister of India on 23rd June 1966.
The University was renamed as Acharya N. G. Ranga Agricultural University on 7th November 1996 in honour and memory of an outstanding parliamentarian Acharya Nayukulu Gogineni Ranga, who rendered remarkable selfless service for the cause of farmers and is regarded as an outstanding educationist, kisan leader and freedom fighter.
HISTORICAL MILESTONE
Acharya N. G. Ranga Agricultural University (ANGRAU) was established under the name of Andhra Pradesh Agricultural University (APAU) on the 12th of June 1964 through the APAU Act 1963. Later, it was renamed as Acharya N. G. Ranga Agricultural University on the 7th of November, 1996 in honour and memory of the noted Parliamentarian and Kisan Leader, Acharya N. G. Ranga. At the verge of completion of Golden Jubilee Year of the ANGRAU, it has given birth to a new State Agricultural University namely Prof. Jayashankar Telangana State Agricultural University with the bifurcation of the state of Andhra Pradesh as per the Andhra Pradesh Reorganization Act 2014. The ANGRAU at LAM, Guntur is serving the students and the farmers of 13 districts of new State of Andhra Pradesh with renewed interest and dedication.
Genesis of ANGRAU in service of the farmers
1926: The Royal Commission emphasized the need for a strong research base for agricultural development in the country...
1949: The Radhakrishnan Commission (1949) on University Education led to the establishment of Rural Universities for the overall development of agriculture and rural life in the country...
1955: First Joint Indo-American Team studied the status and future needs of agricultural education in the country...
1960: Second Joint Indo-American Team (1960) headed by Dr. M. S. Randhawa, the then Vice-President of Indian Council of Agricultural Research recommended specifically the establishment of Farm Universities and spelt out the basic objectives of these Universities as Institutional Autonomy, inclusion of Agriculture, Veterinary / Animal Husbandry and Home Science, Integration of Teaching, Research and Extension...
1963: The Andhra Pradesh Agricultural University (APAU) Act enacted...
June 12th 1964: Andhra Pradesh Agricultural University (APAU) was established at Hyderabad with Shri. O. Pulla Reddi, I.C.S. (Retired) was the first founder Vice-Chancellor of the University...
June 1964: Re-affilitation of Colleges of Agriculture and Veterinary Science, Hyderabad (estt. in 1961, affiliated to Osmania University), Agricultural College, Bapatla (estt. in 1945, affiliated to Andhra University), Sri Venkateswara Agricultural College, Tirupati and Andhra Veterinary College, Tirupati (estt. in 1961, affiliated to Sri Venkateswara University)...
20th March 1965: Formal inauguration of APAU by Late Shri. Lal Bahadur Shastri, the then Hon`ble Prime Minister of India...
1964-66: The report of the Second National Education Commission headed by Dr. D.S. Kothari, Chairman of the University Grants Commission stressed the need for establishing at least one Agricultural University in each Indian State...
23, June 1966: Inauguration of the Administrative building of the university by Late Smt. Indira Gandhi, the then Hon`ble Prime Minister of India...
July, 1966: Transfer of 41 Agricultural Research Stations, functioning under the Department of Agriculture...
May, 1967: Transfer of Four Research Stations of the Animal Husbandry Department...
7th November 1996: Renaming of University as Acharya N. G. Ranga Agricultural University in honour and memory of an outstanding parliamentarian Acharya Nayukulu Gogineni Ranga...
15th July 2005: Establishment of Sri Venkateswara Veterinary University (SVVU) bifurcating ANGRAU by Act 18 of 2005...
26th June 2007: Establishment of Andhra Pradesh Horticultural University (APHU) bifurcating ANGRAU by the Act 30 of 2007...
2nd June 2014 As per the Andhra Pradesh Reorganization Act 2014, ANGRAU is now...
serving the students and the farmers of 13 districts of new State of Andhra Pradesh with renewed interest and dedication...
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ThesisItem Open Access OCCURRENCE, PATHOGENIC VARIABILITY AND MANAGEMENT OF TURCICUM LEAF BLIGHT OF MAIZE(guntur, 2022-08-17) HONEY DEW, U.; ANIL KUMAR, P.Survey in Guntur district revealed 29.03% (PDI) of Turcicum leaf blight incidence caused by Exserohilum turcicum. Severity in the surveyed mandals ranged from 26.84 to 30.41% PDI during rabi 2019-20. Variability in cultural characters was assessed at 8 DAI on PDA. All the isolates showed considerable variation in terms of color, pigmentation, colony character, growth habit, nature and texture of mycelium. Six types of colony colours were observed in all the isolates viz. gray, dark grayish brown, very dark grayish brown, very dark gray, olive brown and greenish black. Dark olive brown, very dark grayish brown, black and greenish black were the four types of pigmentation observed in the test E. turcicum isolates where blackish pigmentation was found to be dominant. Circular, oval and irregular colony margins were observed. Aerial, aerial and submerged, and submerged were the types of growth habits observed. All the test E. turcicum isolates showed two different textures: cottony and flocculant. Average growth rate of each isolate also showed significant variation where a maximum growth rate was recorded in two isolates HMEt-20-02 and HMEt-20-16 with 0.46 mm h-1 followed by HMEt-20-01 at a growth rate of 0.45 mm h-1 while a minimum of 0.06 mm h-1 was recorded in the isolate HMEt-20-14. Among all the isolates, the highest spore production was recorded in HMEt-20-19 and HMEt-20-02 each with 0.48 × 104 spores/mm2 followed by HMEt-20-04 and HMEt-20-13 with 0.47 × 104 spores/mm2 and 0.46 × 104 spores/mm2 respectively. The least sporulating isolate was found to be HMEt-20-03 with 0.01 × xv 104 spores/mm2. Conidiophore length and breadth varied from 106.67 ± 23.88 μm to 291.88 ± 52.25 μm and 4.17 ± 0.93 μm to 7.97 ± 0.45 μm respectively. Conidial size ranged from 42.26 ± 7.74 μm × 65.45 ± 14.35 μm × 6.94 ± 1.34 μm to 15.03 ± 2.00 μm while the number of septa varied from 4.65 ± 1.18 to 7.15 ± 1.39. Germination pattern was recorded in all the isolates and all of them showed unipolar germination which was the characteristic feature of E. turcicum. Variability in molecular characters was analysed using eight arbitrary RAPD primers among different test E. turcicum isolates. A total of 58 bands were obtained from the four primers which showed 100% polymorphism and the band size ranged from 100 to 1300 bp. PIC (Polymorphic Information Content) values varied from 0.40 to 0.45. OPA-03 primer recorded the highest PIC (0.45) while the least PIC value (0.40) was observed in case of OPA-08 and an average PIC value of 0.45 was obtained. The coefficient of similarity varied from 0.43 to 1.00. The least similarity (0.43) was recorded between HM Et 20-04 & HM Et 20-09 and HM Et 20-05 & HM Et 20-16 while the highest similarity (0.81) was observed in case of HM Et 20-01 and HM Et 20-02. The dendrogram obtained showed two major clusters or groups. Of the two major clusters, 19 isolates belonged to one cluster while HM Et 20-18 isolate deviated to be a lone cluster. The lone cluster showed 54% dissimilarity when compared to the other major cluster. The highest similarity of 81% was observed between the isolates, HM Et 20-01 and HM Et 20-02 that belonged to the same mandal. Within the same mandal also variation existed, indicating the presence of different isolates. On the contrary, isolates from different mandals also found to be similar irrespective of geographic locations. Under in vitro conditions, mancozeb @ 0.25%, zineb @0.25%, pyraclostrobin+epoxiconazole @ 0.5% and difenconazole @ 0.15% were found effective in inhibiting the mycelial growth of E. turcicum. From in vitro dual culture experiments, four biocontrol agents, HMP A 02, HMP Bc 03, HMP Pf 01 and T 19023 were found best in inhibiting radial growth of the pathogen. Among the test treatments, at 14 days after second spray (64 DAS), difenconazole @0.15% recorded the lowest PDI (14.00%) and a minimum area under disease progress curve of 359.33 as against untreated control (873.32). Maximum yield was recorded in treatment with difenconazole @0.15% (7448.81 kg ha-1) and mancozeb @0.25% (7328.57 kg ha-1). The benefit cost ratio varied from 1.49 to 2.54 with highest recorded BC ratio (2.54) in the treatment difenconazole @0.15% against unsprayed check (1.49).ThesisItem Open Access MANAGEMENT OF SORGHUM TURCICUM LEAF BLIGHT USING BACTERIAL ENDOPHYTES(guntur, 2022-08) KAVYA, NATI; PRASANNA KUMARI, V.The present research on “Management of sorghum Turcicum leaf blight using bacterial endophytes” was carried out at the Department of Plant Pathology, Agricultural College, Bapatla. A total of 13 bacterial endophytes were isolated and designated based on the plant part from which they were isolated. Number of endophyte colonies was consistent in occurrence irrespective to the age of the leaf used for isolation, but was high from roots. The incubation period of 2.0 to 2.8 days was required for bacterial expression in sap inoculated samples. However it extended to 4.6 days with leaf bits. Morphologically most of the endophytes from the roots and leaf bits were round with few exceptions while most of the isolates from the leaf sap were irregular except SLSE-01 which was round in shape. Culture characters of the isolates had even to undulated colony margins with an exception with SLSE-05 to be lobate. Eight of the isolates were with raised colonies, while five isolates SLBE-02, 03, 05 and SLSE-01, 05 were flat. Most of the colonies had smooth texture with opaque nature except SRSE-02 and 03 which were translucent. Most of the isolates were creamy white while, SRSE-02, SRSE-03, SLBE-01 and SLSE-05 isolates were white colour and, SLBE-04 was cream coloured. Antagonistic studies revealed endophyte SRSE-01 with 52.75 % inhibition and was found significantly superior over other endophytes isolated from healthy leaf bits, root sap and leaf sap. SLSE-04 (51.65%), SLSE-05 (51.10%) and SLSE-03 (50.00%) isolates of leaf sap were found on par with each other and superior over endophytes from leaf bits. At interaction zone variation in growth pattern of fungus xiii with thickening of the hyphal strands (SRSE-01 and SLSE-02), anastomosis (SRSE-01, SLBE-02 and SLSE-05) and chlamydospores formation was observed. SRSE-01 was significantly superior over other isolates with high number of chlamydospores (222.67/ microscopic field) followed by SLSE-04 (135.33/ microscopic field) and SLSE-05 (117.67/ microscopic field) which were on par with each other. Lysis of the fungal mycelium was not observed in any of the interactions. In detached leaf technique all the isolates were superior over control in per cent spotted area, isolates SRSE-01 was found superior with minimum diseased area of 0.38 cm2 and with least per cent spotted area of 2.29% and was on par with SLSE-05 isolate (2.67%). No significant difference was observed among the isolates with respect to disease index. Based on the superior characters of SRSE-01, SLSE-04, SLSE-05 isolates in dual culture and detached leaf techniques, were advanced for other studies when found compatible with each other. All the three isolates tested positive for biochemical characters such as utilization of nitrogen sources, production of proteases, amylase and catalase whereas they failed to produce siderophore and IAA. SRSE-01 and SLSE-05 were found to solubilize phosphate indicating their ability in phosphate solubilization. Zone of solubilization around their colonies was more pronounced in SLSE-05 isolate compared to SRSE-01 isolate. Phenols content was found significantly high in the treatment where all the endophytes were simultaneously inoculated (2.06 mg g-1) compared to other treatments where endophytes are associated, however it was not superior over phenol from fungicide treated plants (2.29 mg g-1). Similarly, under green house conditions combination of all the three bacterial endophytes resulted in significantly high inhibition of disease (40.70%) at 64 DAS with minimum AUDPC value of 516.35 as against the control (739.53).ThesisItem Open Access STUDIES ON Tobacco streak virus (TSV) CAUSING PEANUT STEM NECROSIS DISEASE (PSND) AND ITS INTERACTION WITH Groundnut bud necrosis virus (GBNV) IN GROUNDNUT (Arachis hypogaea L.)(guntur, 2022-08-17) SARATBABU, K.; VEMANA, K.Groundnut is an annual legume crop grown in diverse environment over the world between 40oN and 40oS. Among the viruses infecting groundnut, Tobacco streak virus (TSV) causing peanut stem necrosis disease (PSND) and Groundnut bud necrosis virus (GBNV) causing Peanut bud necrosis disease (PBND) are major constraints for groundnut cultivation in India. Extensive survey was so far not conducted in groundnut growing districts of A.P. and very limited research was carried out regarding screening of groundnut genotypes against PSND in both field and artificial conditions in glass house. Cloning of resistant gene analogues (RGA), morphological and biochemical parameters responsible for resistance against PSND in groundnut genotypes were not attempted. Further, mixed infection of TSV and GBNV, and their combined impact on groundnut cultivation have not been studied to date. In this context, diagnostic surveys were conducted to determine the incidence of viral diseases in groundnut growing districts of Andhra Pradesh (A.P). Studies on identification of resistance sources against TSV in groundnut genotypes through natural infection and artificial sap inoculation, identification of resistance to Tobacco streak virus (TSV) using resistance gene analogue in groundnut genotype and interaction of TSV and GBNV in groundnut was carried out at Agricultural Research Station, Kadiri from 2017 to 2020. Roving survey was conducted for assessing the incidence of viral diseases in 12 districts of A.P. during kharif and rabi 2017-18. Major viral diseases such as PSND and PBND was observed during the survey. Mean PSND incidence was significantly higher in kharif 2017-18 (7.4%) compared to rabi 2017-18 (6.5%) in groundnut growing districts of A.P. The present study recorded PSND incidence for the first time from four coastal A.P. districts (Krishna, Guntur, Sri Pottisriramulu Nellore, Prakasham) with confirmation using DAC-ELISA and RT-PCR. The partial coat protein (CP) gene of TSV-GN-INDVP groundnut isolate shared wide range of nucleotide identities (80.72-98.62 %) with isolates reported globally. Present study isolate shared 97.97-98.51% xiv nucleotide identities with groundnut isolates and 97.51-98.62 % nucleotide identities with other crop TSV isolates from India. Of the 70 fields surveyed, spread over twelve districts of A.P., 66 fields showed infection of GBNV revealing wide spread occurrence of the disease in A.P. Roving survey revealed that PBND incidence was significantly higher in rabi 2017-18 (13.6%) compared to kharif 2017-18 (5.3%) in groundnut growing districts of A.P. Partial nucleocapsid (N) protein gene of GBNV-GN-BPIND groundnut isolate shared high range of nucleotide identity (78.66-98.48 %) with other GBNV isolates reported from different crops and locations. GBNV-GN-BPIND isolate shared 96.67-97.73 per cent nucleotide identity with groundnut isolates and 96.59–98.48 per cent nucleotide identity with GBNV isolates of other crops from India. Sixty-two genotypes (Elite, pre-released and interspecific cross derivatives) screened against PSND for two seasons (kharif 2017-18 and kharif 2018-19) by Parthenium infector border and natural conditions (without infector border). Field screening of genotypes revealed that the genotypes ICGV-06175, ICGV-06145, ICGV-06149 and genotypes viz., K-7 bold, Kadiri Lepakshi, K-9, K-1909 performed consistently highly resistant and resistant reaction respectively in field conditions for two seasons (kharif 2017-18 and 2108-19). Above resistant genotypes along with susceptible genotypes viz., ICGV07120, K-1811, Kadiri Harithandra, Kadiri Amaravathi, K-2269 (E), K-1482K-, ICG14373, K-1628 (HY), K-2270, GPBD-4, 1501 (FDR), 1559 (FDR), Kisan were selected for further studies under glasshouse condition to confirm their resistance against TSV by mechanical sap inoculation at 14 DAS. The per cent disease incidence was recorded 3-10 days’ post inoculation (DPI) ranged from 37.5 to 100% among the genotypes. The minimum incidence was recorded in ICGV-06175 and showed significant difference with other genotypes. The genotypes grouped under highly resistant, resistant categories in field screening became susceptible in glasshouse during TSV sap inoculation. The genotypes which are given highly resistant (ICGV-06175, ICGV-06145, ICGV-06149), resistant (K-7 bold, Kadiri Lepakshi, K-9, K-1909), susceptible (Kisan) reaction under field condition were selected to isolate RGAs using PCR based approach and successfully isolated RGAs from genomic DNA of TSV highly resistant, resistant and susceptible groundnut genotypes. As compared to highly resistant and resistant genotypes, susceptible genotype showed faint band amplification and analysis of derived peptide sequences revealed that deletion of amino acid sequence in P-loop motif and expressed shift of amino acids such as aspartic acid (D) to serine (S) and leucine (L) to valine (V) in non-TIR-NBS LRR sub family when compared to resistant and tolerant genotypes. In highly resistant genotypes RGA clones viz., RGA 12 (ICGV06175) and RGA14 (ICGV06145) in TIR- NBS LRR sub family expressed shift of amino acid leucine (L) to serine (S) when compared to resistant and susceptible genotypes. During simultaneous inoculation no synergism was observed between TSV and GBNV, while a slight antagonism was observed between these viruses. But this antagonism reaction didn’t help the plant in avoiding disease. Based on reaction under high disease pressure (using Parthenium infector border) under field condition and artificial sap inoculation under glasshouse conditions the genotype ICGV06175 was identified as highly resistant against PSND and can be used in breeding program as a resistant source against PSND. The isolated RGAs from groundnut genotypes can be used for characterization of different resistant genes and can be explored in the development of disease resistance molecular markers.ThesisItem Open Access STUDIES ON VIRAL DISEASES INFECTING GROUNDNUT (Arachis hypogaea L.)(guntur, 2022-08-11) TEJASWINI, PULAVARTHI; MANOJ KUMAR, V.The present investigation on “Studies on viral diseases infecting groundnut (Arachis hypogaea L.) was carried out at Agricultural College, Bapatla, Guntur district, Andhra Pradesh during kharif and rabi 2020-21. Roving survey was conducted in two major groundnut growing districts of Andhra Pradesh viz., Guntur and Prakasam which falls under Krishna-Godavari zone on the basis of agroclimatic zones during kharif and rabi 2020-21 revealed the incidence of peanut stem necrosis disease (PSND) caused by Tobacco streak virus in the range of 2.0-11.5% and 0.0-7.7% respectively and incidence of groundnut bud necrosis disease (GBND) caused by Groundnut bud necrosis virus in the range of 0.0-4.6% and 0.0-3.25% respectively during kharif 2020-21. In rabi 2020-21, incidence of PSND was in the range of 0.0-1.75% in Guntur district and no incidence was recorded from Prakasam district, per cent incidence of GBND was in the range of 0.0-12.45% and 0.0-9.9% in Guntur and Prakasam districts respectively. Under field conditions, symptoms of peanut stem necrosis disease (PSND) appeared as localized necrotic spots which later got spread to petiole, bud and stem as continuous necrotic streaks and eventually led to the death of the plant. Groundnut bud necrosis disease symptoms appeared as mild chlorotic mottle or spots which later developed into chlorotic rings and necrotic rings on young quadrifoliate leaves of groundnut. Further, the necrosis extended to petiole and to the growing terminal buds, finally to the stem and resulted in proliferation of axillary shoots and stunting. Mechanical sap inoculations of representative TSV isolate from groundnut, TSV-Karlapelm on to cowpea (Vigna ungiculata cv. PUSA KOMAL) exhibited chlorotic and necrotic spots within 3-5 days of post-inoculation while representative GBNV isolate from groundnut, GBNV-Bapatla (GBNV-GN-INDBPT) exhibited chlorotic spots and distinct chlorotic rings within 4-7 days of post inoculation. xvi The partial coat protein (CP) gene of representative TSV-BPT-KP groundnut isolate shared a wide range of nucleotide identities (79.9-98.7%) with the isolates reported globally. It shared 98.1-98.7% nucleotide similarities with groundnut TSV isolates and 97.9-98.7% nucleotide similarities with other crop TSV isolates from India. The partial movement protein (MP) gene of representative TSV-GN-INDKP groundnut isolate shared a wide range of nucleotide identities (87.4-99.2%) with the isolates reported globally. It shared 98.9-99.2% nucleotide similarities with groundnut TSV isolates and 95.1-99.2% nucleotide similarities with other crop TSV isolates from India. The partial nucleocapsid (N) protein gene of the present study isolate (GBNV-GN-INDBPT) shared a wide range of nucleotide identity (86.2-98.6%) with other GBNV isolates reported from different crops and locations. GBNV-GN-INDBPT isolate shared 97.0-97.2% nucleotide similarities with other groundnut isolates and 86.2-98.6% nucleotide similarities with other crop GBNV isolates from India. Seed treatment with thiamethoxam @ 2 g kg-1 seed along with two foliar sprays of thiamethoxam 25 WG @ 0.2 g l-1 at 20 DAS and 45 DAS recorded significantly low incidence of PSND, GBND, population of thrips per terminal bud and also improved shoot length, root length, dry pod yield, number of pods per plant, 100 seed weight, shelling percentage and it was found economical.ThesisItem Open Access STUDIES ON POKKAH BOENG DISEASE OF SUGARCANE INCITED BY FUSARIUM SPP.(guntur, 2022-08) MANJULA; ANIL KUMAR, P.The present investigation on “Studies on Pokkah boeng disease of sugarcane incited by Fusarium spp.” was conducted at Department of Plant Pathology, Bapatla and at RARS, Anakapalle during 2020-21, where 44 fields running across 15 villages in seven mandals of Visakhapatnam district, A.P were surveyed, Pokkah boeng incidence was recorded upto a maximum of 40% indicating impact of disease. All the twenty isolates obtained from the surveyed villages showed pathogenicity by producing Pokkah boeng symptoms such as malformed spindle leaves, red specks or stripes on chlorotic area and shot holes. Cultural characterization for these isolates showed variation in colony colour, reverse pigmentation, growth habit, nature and texture of mycelium. Variability in morphological characters were noticed such as macro and micro conidial length and width along with their shape, presence or absence of chlamydospore, mono or polyphialidec conidiophore. ITS marker with amplicon size ~500 bp generally used for fungi and TEF-α primer with amplicon size ~300 bp confirmed the isolates as Fusarium sacchari for 19 out of 20 isolates, where isolate F 14 which was found to be F. andiyazi through BLAST analysis. Phylogenetic tree using both ITS and TEF-α primer showed remarkable evolutionary relationship between these two species by forming two separate clades with 40% and 62 % similarity, respectively. F. andiyazi, a new species on sugarcane causing Pokkah boeng disease was first time noticed in India. Based on in-vitro poisoned food technique against F. sacchari, fungicides such as carbendazim, difenoconazole, tebuconazole, propiconazole, azoxystrobin + difenoconazole and trifloxystrobin + tebuconazole were found to be highly effective with 100% inhibition of radial growth of mycelium, both at 500 and 1000 ppm concentrations followed by azoxystrobin + tebuconazole. Azoxystrobin, copper oxychloride and mancozeb alone showed poor inhibition. xiv In vitro dual culture studies with bacterial bioagents (isolated from sugarcane phylloplane) against F. sacchari revealed significant efficacy of ScANKP-9 and ScANKP-13 isolates with 50.33 and 46.67 per cent inhibition of radial growth of pathogen respectively. These effective bacterial isolates were confirmed as Bacillus amyloliquefaciens (ScANKP-9) and Pseudomonas fluorescence (ScANKP-13) respectively, through molecular characterization. Studies on screening of sixty two sugarcane germplasm entries for resistance against Pokkah boeng disease with three highly susceptible check varieties revealed that six from IVT entries (CoV 18357, CoOr 18346, CoA 92081(c), CoC 01061 (c), CoOr 03151 (c) and CoA 11321 (c)), one from AVT І early entries (CoA 17321), one from AVT ІІ early entries (CoC 16337), three from AVT ІІ mid late entries (CoV 92102, Co 86249, Co 06030), five from PYT entries (2017A 268, 2017A 405, 2017A 408, 2017A 416, 2017A 269) and eleven from MYT entries (2016A 128, 2016A 275, 2016A 291, 2016A 332, 2016A 387, 2016A 737, 2016A 165, 2016A 254, 2016A 276, 2016A 286, 2016A 743) were found to be resistant with less than 5% disease incidence. Varieties such as CoV 18356 (IVT entries), CoC 17336 (AVT I Early entries), CoV 16356 (AVT II Early entries), CoC 16339 (AVT II Mid late entries) were highly susceptible with more than 20% disease incidence.ThesisItem Open Access STUDIES ON INTERACTION DYNAMICS OF TRICHODERMA AND FUSARIUM OXYSPORUM IN RELATION TO WILT OF CHICKPEA(guntur, 2022-08-11) AMULYA, G.; ANIL KUMAR, P.In the present investigation on "Studies on interaction dynamics of Trichoderma and Fusarium oxysporum in relation to wilt of chickpea", 24 fields running across 12 villages in six mandals of Prakasam district, A.P were surveyed for the prevalence of Chickpea Fusarium wilt caused by Fusarium oxysporum f. sp. ciceri (Foc). The Fusarium wilt incidence ranged from 59.88% to 100% indicating impact of disease. Twenty four each of Foc and Trichoderma isolates were collected from the surveyed villages and studied for variability along with one isolate each of Foc and Trichoderma collected from College Farm, Agricultural College, Bapatla. Variability in Foc isolates was assessed for morphological characters such as macro and micro conidial length and width and cultural characters viz. medium pigmentation, texture, colony elevation, growth habit, colony margin and nature of mycelium. Based on the characters studied, 25 test isolates of Foc were segregated into different groups. Variability in Foc pathogenicity was observed in pot culture as effect on seed germination and wilt incidence. All the isolates were found equally pathogenic in causing wilt, though variation existed in affecting seed germination. SCAR marker with an amplicon size of ~207 bp specific to Foc was developed from Foc0-12 RAPD marker sequence of AF492451.1 clone available in genbank NCBI. Specificity and reliability of the SCAR marker was further confirmed by assessing F. moniliforme, other species of Fusarium and different other genera for which the result was negative. xx Variability assessment among the 25 test isolates of Trichoderma used in the present investigation was studied using the cultural and morphological characters. The 25 test isolates, accordingly were identified as T. longibrachiatum (4 No.s), T. pseudokoningii (1 No.s), T. virens (3 No.s), T. aureoviride (2 No.s), T. harzianum (4 No.s), T. asperellum (7 No.s) and T. viride (4 No.s). Molecular analysis of Trichoderma isolates using ITS primers revealed two clusters with 61% similarity. Based on studies on in-vitro dual culture studies, volatile and non volatile metabolites of Trichoderma and volatile metabolites of Foc and compatibility with biorationals, Trichoderma isolate T 19001 was selected as the most potential isolate for biocontrol of Foc. T 19001 was found to be effective under green house conditions when integrated with panchagavya, by not only increasing germination, root length and shoot length of chickpea, but also significantly reduced the disease incidence over pathogen check. Pooled analysis of the field experiment conducted during rabi 2018-19 and 2019-20 to assess the biocontrol potential of T 19001 in integration with biorationals revealed that seed treatment with T 19001 + Panchagavya @ 10% resulted in maximum disease control (35.9%) of chickpea wilt complex, yield (1586.5 kg/ha) and B:C ratio (2.40) and was on par with Tebuconazole seed treatment (1672.0 kg/ha and 2.42 B:C ratio). Beejaraksha and beejamrutha were inferior to panchagavya either alone or in integration with T 19001. Studies on interaction dynamics of Foc and T 19001 in pot culture revealed that T 19001 could lower the population of Foc and thereby decreasing chickpea wilt incidence. Further, increased dose / cfu of Foc warrants increased dose / cfu of T 19001 indicating that dose of Trichoderma should depend on the cfu of Foc in soil for better disease management tactics.ThesisItem Open Access CHARACTERIZATION OF MAIZE BANDED LEAF AND SHEATH BLIGHT PATHOGEN AND ITS MANAGEMENT(guntur, 2022-08-11) GUNASRI, REDDI; PRASANNA KUMARI, V.In the present investigation on “Characterization of Maize Banded Leaf and Sheath Blight Pathogen and its Management”, survey during rabi, 2018-19 in five major maize growing districts of A.P. revealed BLSB to an extent of 61.35% (West Godavari), 58.05% (East Godavari), 46.87% (Vizianagaram), 25.85% (Guntur) and 23.02 % (Kurnool). In vitro studies on cultural and morphological variability of 18 R. solani f. sp. sasakii isolates obtained from maize growing areas of A.P. indicated that colony colour was initially white later varied to light yellowish brown (6/3-2.5 Y), light brown (6/3-7.5 YR), pale brown (6/3 10YR) and brownish yellow (6/6 10YR). Of the isolates RWGB-01, REGP-05, REGJ-07, REGK-08, RVZM-10, RVZB-11 were found superior in their radial growth (9.00 cm) with high growth rate (0.75 mm h-1). Four different growth patterns with profuse aerial mycelium were observed. Hyphal width among isolates ranged from 6.69 to 8.66 μm (RWGB-01). The sclerotia size varied from 0.93 (RKLC-18) to 1.86 mm (RWGB-01 and RWGN-03) and sclerotia weight ranged from 5.97 (RKLR-17) to 61.32 mg (RGUG-13). Time taken to form sclerotia varied from five to eight days with wide variation in colour. Three different types of sclerotial distribution were observed, i.e., aerial, surface and, surface and aerial. Five Different types of patterns of arrangement of sclerotial bodies in culture plates were observed. Sclerotia number ranged from 10 to 122. Two types of sclerotia textures i.e., rough and smooth were observed. xvii The incubation period varied from 72 to 120 h. Among all the isolates, REGP-05 isolate was found highly virulent with low incubation period (72 h) resulting in large lesions (22.43 cm) and highest PDI (49.33%). Molecular variability was determined for the 18 test isolates using four RAPD and two ISSR primers which resulted in a total of 108 bands with polymorphism having band size ranged from 300 to 3000 bp. Dendrogram obtained had two clusters (I and II), cluster I consisted of single isolate (RGUG-13) and cluster II consisted of remaining 17 isolates. Cluster I had 66% similarity with cluster II. The average PIC value (0.27) was similar to both the primers whereas average Rp value was high for ISSR primers (6.21) when compared to RAPD primers (5.92). Isozyme variability in esterase and peroxidase enzymes was determined for the R. solani f. sp. sasakii isolates. A total of 18 bands with Rm values ranging from 0.24 to 0.54 were obtained. Dendrogram obtained had three clusters (A, B and C). Cluster A consisting of two isolates RWGN-03 and RWGD-04 while cluster B consisting of four isolates (RWGK-02, REGJ-07, REGK-08 and RVZS-09). Cluster C was comprised of remaining 12 isolates. Cluster A was 60% similar to cluster B, C and cluster B was 75% similar to cluster C. Under in vitro conditions Karanj leaf extract @ 15% resulted in the maximum mycelial inhibition of pathogen (3.18 cm) followed by Karanj leaf extract @ 10% (4.12 cm) and Nerium leaf extract @ 5% (4.50 cm). Among all the tested cow based natural products (CBNP), Panchagavya was significantly superior in inhibiting the radial growth of the pathogen at all the concentrations, i.e., 5%, 10%, 15% (0.00 cm) and was on par with the cow urine @ 10, 15% (0.00 cm) and cow dung + cow urine @ 15% (0.00 cm). Pooled data analysis of both the seasons (rabi 2018-19 and 2019-20) revealed efficacy of Karanj leaf extract @ 15%+Panchagavya @ 5% in controlling the disease even two weeks after second spray (71 DAS) with low PDI (35.77%) and minimum AUDPC (670.60) compared to unsprayed check (1137.16). Treatment Karanj leaf extract @ 15%+Panchagavya @ 5% recoded maximum number of cobs/m2 (9), test weight (22.83 g), yield (7469.14 Kg ha-1) and B: C ratio (2.55) as against the control (1.43).ThesisItem Open Access INVESTIGATIONS INTO ANTAGONISTIC BASIS OF ROOT ENDOPHYTIC BACTERIA IN THE CONTROL OF CHICKPEA DRY ROOT ROT PATHOGEN (Rhizoctonia bataticola (Taub.) Butler)(ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, GUNTUR, 2021-12-21) CHIRANJEEVI, N; REDDI KUMAR, MA survey was conducted during January, 2017 Rabi season in five major chickpea growing districts of Andhra Pradesh viz., Kurnool, Y.S.R Kadapa, Anantapuramu, Prakasam and Guntur to assess the status of dry root rot incidence under field conditions. Mean maximum dry root rot incidence was observed in Anantapuramu (11.50 %) followed by Kurnool (9.61 %), Y.S.R Kadapa (7.92 %) and Prakasam (7.50 %) and the least was observed in Guntur (6.00 %). Disease occurrence was observed irrespective of cropping system, soil types and cultivars. The disease incidence was low in the irrigated fields compared to rainfed fields. A total of 22 isolates of R. bataticola were obtained and purified by single sclerotial isolation technique. Variability in the cultural and morphological characters of 22 isolates of R. bataticola were studied by growing on potato dextrose agar medium. Among all the isolates CRb 10 taken significantly least time (2.50 days) to occupy the full plate and higher radial growth at 42 hrs was observed with CRb 10 isolate (75.78 mm). However, fluffy colonies were produced by CRb 2 and CRb 15 isolates while, velvety colony texture was observed with CRb 13 and remaining all the isolates showed appressed colony texture. Similarly, out of 22, jet black, light black and grey colour mycelia was observed in total of seventeen, four and one isolates respectively. Among all the isolates, significantly maximum time was taken by CRb 18 isolate for sclerotial initiation and least time was taken by CRb 16 (1.83 days). However, among the isolates higher number of sclerotia per 10 x microscopic field and sclerotial size was observed with CRb 16 (33.33) and CRb 6 (119.32 µm) respectively. Similarly, among 22 isolates, irregular, ovoid and round shaped sclerotia were observed in total of 3, 9 and 10 isolates respectively. Pathogenicity of R. bataticola isolates was proved by soil inoculation method. When observations were collected on disease incidence (%), among the isolates tested maximum disease incidence (100 %) was observed in CRb 9 and it was considered as a most virulent pathogen isolate and used for further studies. A total of 40 antagonistic endophytic bacteria were isolated from healthy roots of different chickpea varieties and the antagonistic efficiency was tested using dual culture technique. Among the isolates CREB 37 showed maximum antifungal efficiency with 74.04 % inhibition against virulent R. bataticola isolate CRb 9. Based on the results it was considered as a potential isolate and used for further studies. Mannitol @ 2 %, soytone @ 2 % pH 7 and temperature 30oC were found to be optimum for cell growth and antibiotic production. Similarly, significant improvement in the cell growth and antibiotic production was observed with the modified Luria broth than the basal medium (Luria broth). Crude antibiotic substances were extracted and tested their bio-efficacy against R. bataticola by agar well diffusion assay. Among the different concentrations tested significantly higher inhibition was recorded at 100 µl (77.23 %). The microscopical examination of the crude antibiotic extract treated mycelia of the R. bataticola revealed its effect on the fungal morphology. Light microscopic analysis revealed that severe mycelial destruction and the SEM images clearly explained the disruption of the fungal hyphae due to the mechanistic effect of antibiotic compounds on fungal cell wall. Among the 14 potential isolates, Gram negative (7) and Gram positive (7) were recorded in equal proportion and all were rod shaped bacteria. Out of the 14 isolates, a total of 9, 7, 2, 1, 2, 3, 3, 13, 6, 3 and 0 showed positive for amylolytic activity (starch hydrolysis), proteolytic activity (Gelatin hydrolysis), lactose utilization, indole production, methyl red test, Voges-Proskeur test, citrate utilization, presence of catalase activity, ammonia production, HCN production and siderophore production respectively. 16S r DNA sequence analysis was used to identify the potential bacterial isolates such as CREB 9, CREB 21 and CREB 37 and which were exhibited close similarity of 97.75, 98.48 and 93.28 per cent with Enterobacter cloacae, Pseudomonas aeruginosa and Bacillus subtilis respectively. Talc based formulation of potential endophytic bacterial isolate B. subtilis (CREB 37) was prepared and tested the bio-efficacy of formulation and crude antibiotic extract in pot culture. Under glasshouse conditions treatment T7 (seed treatment with potential bacterial antagonist (talc formulation) @ 10 g kg-1 + soil application with talc based formulation of potential bacterial antagonist @ 100 g pot-1) was found to be superior as it recorded maximum germination per cent, plant height, root length, dry weight and least per cent disease incidence compared to other treatments.ThesisItem Open Access INVESTIGATIONS ON PREVALENCE, TRANSMISSION AND MANAGEMENT OF STERILITY MOSAIC DISEASE OF PIGEONPEA (Cajanus cajan (L.) Millsp.)(Acharya N.G. Ranga Agricultural University, Guntur, 2021-12-09) SAYIPRATHAP, B. R.; ANIL KUMAR, Dr. P.Sterility mosaic disease (SMD) is caused by Pigeonpea sterility mosaic virus (PPSMV). Strain variability coupled with recent characterization of another Emaravirus (PPSMV-II) made a complex etiology of this difficult to manage the viral disease. In this context, the present study was carried out at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Hyderabad, Telangana from 2017 to 2019 to determine the prevalence of SMD, variability in PPSMV isolates in southern India, host range, the occurrence of different strains and to find out broad-based resistance source in pigeonpea genotypes. A comprehensive and systematic survey was conducted in southern India during the 2017 rainy season indicated a huge variation in disease incidence ranging from 0-47.50 per cent. In Andhra Pradesh, less SMD incidence (0.06 %) was recorded Guntur district While, in Anantapur and Chittoor districts, the disease incidence was 5.90 per cent and 11.80 per cent respectively. In Karnataka, SMD was found to be a major production constraint throughout the state. Among the ten districts surveyed, higher disease incidences of 14.71 and 19.78 per cent was recorded in Gulbarga and Kolar district respectively. In Tamil Nadu, less SMD incidence (4.08 %) was observed in the Pudukottai district, whereas, highest disease incidence was recorded in the Krishnagiri district (16.25 %). In Telangana, there was less incidence of SMD in all surveyed locations that ranged from 0 to 8.0 per cent. In the Nalgonda district, SMD incidence was 0.60 per cent, whereas, in Medak district, it was 1.50 per cent. Analysis of the RNA-3 partial nucleotide sequence identity among the seven isolates of PPSMV-I and PPSMV-II in southern India indicated significant sequence variability. Among the 11 Nicotiana species and five herbaceous plants tested for PPSMV infection by sap inoculation, the virus successfully transmitted on to Nicotiana benthamiana but not on to the pigeonpea. Of the 24 accessions of 12 wild Cajanus species, xii 16 cultivated crop species and 46 weed species tested by mite inoculation, Cajanus platycarpus, C. scarabaeoides, and C. lancedatus, Phaseolus vulgaris cvs. Top crop, Kintoki, and Bountiful (F: Fabaceae), and weed species, Crozophora rottleri(F: Euphorbiaceae) were infected with both the virus (PPSMV-I and PPSMVII). Though few mites were observed on a weed species Macroptilum atropurpureum (F: Fabaceae), the virus was not infected. The pigeonpea sterility mosaic disease (SMD) samples were collected from three hotspot locations (Patancheru, Bengaluru, and Coimbatore) in southern India when tested for infection of PPSMV-I and PPSMV-II by RT-PCR, all the samples from Patancheru location were found mixed infection of both the viruses. Whereas, few samples from Bengaluru and Coimbatore were found infected with only PPSMVII. There is a significant sequence variability in partial nucleotide sequences of the RNA-1 and RNA-2 segments of PPSMV-I and PPSMV-II isolates in southern India. Interestingly nucleotide sequences of RNA-1 and RNA-2 segments of PPSMV-II isolates showed close relationship with Fig mosaic virus (FMV) than PPSMV-I. This suggested that these two emaraviruses infecting pigeonpea have followed two independent evolutionary paths. Sap transmission inoculation of PPSMV on to Nicotiana species, mite transmission inoculation on to wild Cajanus species, cultivated crop and weed species, as well as random inoculation and single mite transmission on to susceptible pigeonpea genotype, ICP 8863 were not successful in separating out PPSMV-I and PPSMV-II from Patancheru inoculum. Hence in the present study, it could not be possible to ascertain the role and severity of individual virus strain in causing SMD in pigeonpea. A comprehensive analysis of data from the two field trials conducted at Bengaluru and Patancheru locations for the management of SMD during the 2018 crop season confirmed that three sprays of proporgite @ 0.15 per cent recorded least SMD incidence (2.00 %) with 80.33 per cent yield increase over control. Spraying of salicylic acid (SA) @ 0.10 mM and gibberellic acid (GA) @ 250 ppm offered reasonably good levels of SMD control as well. Twenty pigeonpea genotypes were screened for broad-based resistance to SMD at Bengaluru, Coimbatore, and Patancheru locations during the 2017-18 and 2018-19 rainy season. The susceptible test genotypes exhibited the typical SMD symptom between 13-16 days of postinoculation (dpi). Among the genotypes, ICPL-16078, ICPL- 16086 and ICPL-16087 were showed resistance reaction (40 % incidence) at the Bengaluru location. Based on the level of disease reaction in evaluated pigeonpea genotypes for two consecutive years, Bengaluru isolates could be considered as severe strain in causing SMD in pigeonpea.