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

Summary 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. Gamma irradiation at 10 krad completely suppresses sprouting regardless of storage temperature. Storage of irradiated potatoes under tropical temperatures is not feasible due to bacterial spoilage. However irradiated tubers can be stored with reduced losses (7 to 30%) for 5–6 months at 10–15 C. Irradiation also eliminates the egg and early larval stages of the tuber moth,Phthorimaea operculella (Zeller), a serious pest of stored potatoes in tropics. Irradiation followed by storage at 10 C thus offer an alternate method for potato storage in tropics.

---

Zusammenfassung Eine Reihe von Versuchen mit zehn indischen, im Handel bedeutsamen Kartoffelsorten wurde von 1971 bis 1975 durchgeführt, um die Verluste nach der Ernte zu bestimmen, die auf verschiedene Faktoren w?hrend der Lagerung von gammabestrahlten und unbestrahlten Knollen unter tropischen (28–32 C) und kühlen (4, 10 und 15 C) Bedingungen zurückzuführen sind. Einzelheiten über die Muster im Versuch 1975 sind in Tabelle 1 angegeben. Die Knollen wurden in einem⁶⁰Co-Bestrahlungsger?t bestrahlt und in weitmaschigen Jutes?cken eingelagert. Die Ergebnisse sind in den Tabellen 2 bis 9 und den Abb. 1–3 dargestellt. Bei tropischen Umgebungstemperaturen wurde die Bakterien-Nassf?ule, verursacht durchErwinia carotovora var.atroseptica, als der Hauptfaktor befunden, der bei eingelagerten Produkten im Verlauf von 3 bis 4 Monaten Verluste von 50 bis 70% brachte. Das Waschen der Knollen in Natriumhypochlorit-L?sung (200 mg verfügbares Chlor pro Liter) oder Verbesserung der Lüftung durch Lagerung in Harassen verminderte das Vorkommen von Nassf?ule unter diesen Bedingungen nicht (Tabelle 5). Die mengenm?ssigen Verluste infolge Auskeimens. Ausschwitzens und Veratmung w?hrend der viermonatigen Lagerung bei Umgebungstemperaturen schwankten von 8 bis 13%. Obwohl die Gammabestrahlung bei 10 krad das Auskeimen bei allen Sorten vollst?ndig unterdrückte, ist die Lagerung von bestrahlten Knollen bei tropischen Umgebungstem-peraturen wegen der hohen bakteriellen Verderbnis nicht m?glich. Nassf?ule kann durch Lagerung der Knollen bei 10 oder 15 C bedeutend verringert werden; bei diesen Temperaturen wird jedoch das Auskeimen beschleunigt, die Knollen werden nach 3 Monaten Lagerung schrumpfig und unbrauchbar. Allein das Gewicht der abgenommenen Keime verursacht einen Verlust von 8 bzw. 16% des Anfangsgewichts der Knollen nach 3 bzw. 6 Monaten Lagerung (Tabelle 6). Eine Kombination von Bestrahlung, gefolgt von Lagerung besonders bei 10 C, scheint eine Alternative zu bieten, und die Lagerverluste auf ein Mindestmass herabzusetzen, obwohl die Verluste im allgemeinen gr?sser als die unter der konventionellen Kühllagerung bei 2–4 C beobachteten sind. Je nach Sorte und Jahreszeit schwankten die gesamten mengenm?ssigen Verluste bei bestrahlten Knollen w?hrend sechsmonatiger Lagerung bei 10 oder 15 C zwischen 7 und 30% gegenüber 5 bis 18% bei unbestrahlten Knollen und 2–4 C Lagertemperatur. Verwendung von Sorten mit besseren Lagerungseigenschaften und Auswahl gut verkorkter und gesunder Knollen für die Bestrahlung kann die Lagerverluste bei 10 bis 15 C weiter verringern. Bestrahlung bei 10 krad eliminierte auch die Eier und frühen Larvenstadien der KartoffelmottePhthorimaea operculella Zel., die eine der zerst?rerischten Sch?dlinge bei eingelagerten Kartoffeln in den Tropen ist (Abb. 1).

---

Résumé Une série d'essais portant sur dix variétés commer-cialement importantes, cultivées en Inde, a été réalisée de 1971 à 1975, pour évaluer, après la récolte, les pertes provoquées par différents facteurs pendant la conservation de tubercules irradiés et non irradiés et placés dans une ambiance tropicale (28–32 C) ou réfrigèrée (4, 10 et 15 C). Le détail des échantillons étudiés en 1975 est donné dans le tableau 1. Les tubercules ont été traités au Cobalt 60 et stockés dans des sacs de jute à grandes mailles. Les résultats sont présentés aux tableau 2 à 9 et figures 1–3. Dans une ambiance tropicale, la pourriture bacté-rienne provoquee parErwinia carotovora var.atroseptica est principalement responsable de 50 à 70% des pertes au cours de 3 à 4 moins de stockage. Le lavage des tubercules dans une solution d'hypochlorite de sodium (200 mg litre de chlore libre) ou l'amélioration de la ventilation en conservant dans des caisses de bois à claire-voie ne réduit pas l'importance de la pourriture sous ces conditions (tableau 5). Les pertes de poids provoquées par la germination, la transpiration et la respiration pendant 4 mois de conservation à température ambiante se situent entre 8 et 13%. Bien que l'irradiation gamma à 10 krad supprime totalement la germination de toutes les variétés, la conservation des tubercules irradiés dans une ambiance tropicale est irréalisable en raison des pertes élevées d'origine bactérienne. La pourriture humide peut être fortement réduite par une conservation à 10 ou 15 C. Cependant, à ces températures, la germination est accélérée, les tubercules se rident et sont inutilisables après 3 mois de stockage, les pertes de poids dues à la germination représentant 8 à 16% après respectivement 3 et 6 mois de conservation (tableau 6). La combinaison de l'irradiation et d'un stockage à 10 C permet de minimiser les pertes bien qu'en général, elles soient plus élevées que celles observées à 2–4 C. Suivant la variété, la saison, les tubercules irradiés perdent en 6 mois de conservation, à 10 ou 15 C, 7 à 30% de leur poids contre 5 à 18% pour les tubercules non irradiés stockés à 2·4 C. L'utilisation, pour l'irradiation, de variétés de bonne conservation choisies parmi celles dont les tubercules se cicatrisent bien, permet à 10 15 C, de réduire les pertes. L'irradiation à 10 krad élimine également les ocufs et les larves précoces de teignePhthorimaea operculella (Zeller) qui est un des insectes qui provoque le plus de dégats dans les stockages de pommes de terre sous les tropiques.

     

Combining superior agronomic performance and terminal heat tolerance with resistance to spot blotch (Bipolaris sorokiniana) of wheat in the warm humid Gangetic Plains of South Asia

Seven hundred twenty-nine lines of diverse wheat germplasm lines were evaluated in eight locations of three countries (India, Nepal and Bangladesh) of South Asia for 5 years (1999–2000 to 2003–2004) through Eastern Gangetic Plains Screening Nursery (EGPSN) organized by CIMMYT South Asia, Nepal, for agronomic performance and tolerance to spot blotch of wheat. Each year, the number of lines represented a new set of 150 lines that included six common checks and a different local check at each of the eight locations. One hundred and five lines, 21 in each year, advanced from EGPSN were also tested for 5 years (2000–2001 to 2004–2005) in five locations of South Asia through Eastern Gangetic Plains Yield Trials (EGPYT) to verify spot blotch tolerance and superior yield performance of the selected germplasm. Many lines yielded significantly more than the best check and possessed high levels of spot blotch resistance under warm humid environments of South Asia. The most promising 25 lines have been listed as sources of strong resistance, with 9 lines better yielding than the best resistant check PBW 343 in fewer days to maturity. Most of these superior lines represented elite CIMMYT germplasm and around half were derived from Kauz and Veery. The line EGPYT 67, Kauz//Kauz/Star/3/Prinia/4/Milan/Kauz, was the best for spot blotch resistance, yield, days to maturity, and 1000 grain weight (TKW). The next two lines in the order of merit were EGPYT 84 (Mrng/Buc//Blo/Pvn/3/Pjb 81) and EGPYT 69 (Chirya3/Pastor). The results demonstrate that additional spot blotch resistant wheat genotypes with high grain yield and TKW, and early maturity, have become available as a result of the regional and international collaboration in South Asia.     

Harnessing Plant Growth Promoting Rhizobacteria Beyond Nature: A Review

Root-associated plant growth promoting rhizobacteria (PGPR) interact with the plant roots and influence plant health and soil fertility. Plant growth promoting rhizobacteria play an important role in plant growth by exerting various mechanisms such as biological nitrogen fixation, growth hormone production, phosphate solubilization, siderophore production, hydrolytic enzyme production, antagonistic activity against fungal pathogens etc. Hence, these are employed as inoculants for biofertilizer and biocontrol activities. This review summarizes various mechanisms of PGPR and their potential for use as inoculants. It shows that their use is a worthwhile approach for exploring disease management in conjunction with other strategies.     

Genetic characterization of Indian peste des petits ruminants virus (PPRV) by sequencing and phylogenetic analysis of fusion protein and nucleoprotein gene segments

Peste des petits ruminants (PPR) is an important viral disease of sheep and goats, endemic in India. The study was undertaken to characterize the local PPRV by sequencing fusion (F) protein and nucleoprotein (N) gene segments and phylogenetic analysis, so as to focus on genetic variation in the field viruses. Selected regions of PPRV genome were amplified from clinical samples collected from 32 sheep and goats by RT-PCR and the resulting amplicons were sequenced for phylogenetic analysis. The phylogenetic tree based on the 322bp F gene sequences of PPRV from five different locations clustered them into lineage 4 along with other Asian isolates. While the 425bp N gene sequences revealed a different pattern of branching, yielding three distinct clusters for Nigerian, Turkey and Indian isolates. Thus, classification of PPRV into lineages based on the N gene sequences appeared to yield better picture of molecular epidemiology for PPRV.     

Diversification of maize (Zea mays L.) through teosinte (Zea mays subsp. parviglumis Iltis & Doebley) allelic

Genetic Resources and Crop Evolution - Zea mays ssp. parviglumis is the progenitor of maize and assume to have tolerance against various biotic and abiotic stresses. It...     

Characterizing the Economic Value and Impacts of Wild Pig Damage on a Rural Economy

Wild pigs are a free-ranging invasive species capable of inflicting significant damage on rural property. Wildlife management personnel may benefit from understanding the negative societal impact of wild pigs. A statewide mail survey of randomly selected landowners was conducted in rural Tennessee counties known to have wild pigs. The economic value of damage caused by wild pigs in 2015 in these counties was estimated at $26.22 million, whereas the cost incurred in control and eradication was $2.09 million. Input-output modeling of damage in these counties on the state’s economy showed $32.8 million in lost industrial output, $4.6 million in lost labor income, and 332 jobs or job equivalents affected. Findings are useful in understanding the types of damage, and the extent of these impacts on the rural economy. They could also facilitate comparing the expected benefit with the cost of control programs in Tennessee and comparable areas facing similar invasions from wild pigs.     

Wheat grain yield and stability assessed through regional trials in the Eastern Gangetic Plains of South Asia

Improving the level and stability of grain yield is the primary objective of wheat breeding programs in the Eastern Gangetic Plains (EGP) of South Asia. A regional wheat trial, the Eastern Gangetic Plains Yield Trial (EGPYT), was initiated by CIMMYT in collaboration with national wheat research programs in Bangladesh, Nepal, and India in 1999–2000 to identify wheat genotypes with high and stable grain yield, disease resistance, and superior agronomic traits for the EGP region. A set of 21 wheat experimental genotypes selected from a regional wheat screening nursery in South Asia, three improved widely grown cultivars (Kanchan, PBW343 and Bhrikuti), and one long-term cultivar (Sonalika) were tested at 9–11 sites in six wheat growing seasons (2000–2005) in the EGP. The 21 experimental genotypes were different in each year, whereas the four check cultivars were common. In each year, one or more of the experimental genotypes showed high and stable grain yield and acceptable maturity, plant height, and disease resistance compared to the check cultivars. Three improved cultivars have already been commercially released in the region through EGPYT and many germplasm lines have been used in the breeding programs as parents. Identification of wheat genotypes with high-grain yield in individual sites and high and stable yield across the EGP region underlines their value for regional wheat breeding programs attempting to improve grain yield and agronomic performance.     

Potential of Fodder Soybean Genotypes for Phosphorus Removal in Poultry Manure-Enriched Soils

Plant-based phosphorus (P) remediation strategies have been suggested to reduce high P accumulation in soil. Eleven fodder soybean genotypes were evaluated to explore their potential for the removal of P from poultry manure-enriched soils. Field experiments were conducted at a site that had a history of heavy poultry manure applications. Green house experiments were conducted using the soils selected for field trials to confirm the results. Harvesting of whole plants, excluding roots of the genotypes, was done at the pod formation stages and plant samples were oven dried at 70°C for three days. The dry samples were ground and analyzed for total P content. Genotype 091734, provided the maximum P removal from amended and unamended soils. Fodder soybean genotypes could play an important role in the extraction of P from poultry manure-enriched soils, which are important from the ecological point of view.     

Breeding crops for reduced-tillage management in the intensive, rice–wheat systems of South Asia

The importance of reduced tillage in sustainable agriculture is well recognized. Reduced-tillage practices (which may or may not involve retention of crop residues) and their effects differ from those of conventional tillage in several ways: soil physical properties; shifts in host–weed competition; soil moisture availability (especially when sowing deeply or under stubble); and the emergence of pathogen populations that survive on crop residues. There may be a need for genotypes suited to special forms of mechanization (e.g. direct seeding into residues) and to agronomic conditions such as allelopathy, as well as specific issues relating to problem soils. This article examines issues and breeding targets for researchers who seek to improve crops for reduced-tillage systems. Most of the examples used pertain to wheat, but we also refer to other crops. Our primary claim is that new breeding initiatives are needed to introgress favourable traits into wheat and other crops in areas where reduced or zero-tillage is being adopted. Key traits include faster emergence, faster decomposition, and the ability to germinate when deep seeded (so that crops compete with weeds and use available moisture more efficiently). Enhancement of resistance to new pathogens and insect pests surviving on crop residues must also be given attention. In addition to focusing on new traits, breeders need to assess germplasm and breeding populations under reduced tillage. Farmer participatory approaches can also enhance the effectiveness of cultivar development and selection in environments where farmers’ links with technology providers are weak. Finally, modern breeding tools may also play a substantial role in future efforts to develop adapted crop genotypes for reduced tillage.     

First report of Calonectria cerciana causing leaf blight of Eucalyptus in northern India

Eucalyptus spp. and their hybrids are frequently cloned and mass planted across farmland tracts and commercial plantations in northern India. It is a viable feeder species to the paper and pulp industries in this region. In 2018 and 2019, during field surveys conducted in northern India, a serious leaf blight disease was frequently observed in E. tereticornis plantations. Isolation from the blighted leaf samples consistently yielded fungal isolates having Calonectria‐like morphology. Morphological features coupled with sequence analysis of partial β‐tubulin (TUB2) and partial translation elongation factor‐alpha (TEF1) gene regions of two fungal isolates confirmed the species as Ca. cerciana. In detached leaf assays and glasshouse inoculation experiments, both isolates produced symptoms similar to those observed on the naturally infected leaves. Koch's postulates were fulfilled by re‐isolating Ca. cerciana from the inoculated leaves. This work is the first to confirm that Ca. cerciana is associated with a serious leaf blight disease of Eucalyptus in northern India and is an important addition to the taxonomy of Calonectria fungi in India.