A CRISPR way for accelerating cereal crop improvement: Progress and challenges

Humans rely heavily on cereal grains as a key source of nutrients, hence regular improvement of cereal crops is essential for ensuring food security. The current food crisis at the global level is due to the rising population and harsh climatic conditions which prompts scientists to develop smart resilient cereal crops to attain food security. Cereal crop improvement in the past generally depended on imprecise methods like random mutagenesis and conventional genetic recombination which results in high off targeting risks. In this context, we have witnessed the application of targeted mutagenesis using versatile CRISPR-Cas systems for cereal crop improvement in sustainable agriculture. Accelerated crop improvement using molecular breeding methods based on CRISPR-Cas genome editing (GE) is an unprecedented tool for plant biotechnology and agriculture. The last decade has shown the fidelity, accuracy, low levels of off-target effects, and the high efficacy of CRISPR technology to induce targeted mutagenesis for the improvement of cereal crops such as wheat, rice, maize, barley, and millets. Since the genomic databases of these cereal crops are available, several modifications using GE technologies have been performed to attain desirable results. This review provides a brief overview of GE technologies and includes an elaborate account of the mechanisms and applications of CRISPR-Cas editing systems to induce targeted mutagenesis in cereal crops for improving the desired traits. Further, we describe recent developments in CRISPR-Cas–based targeted mutagenesis through base editing and prime editing to develop resilient cereal crop plants, possibly providing new dimensions in the field of cereal crop genome editing

First Report of Common Bean (Phaseolus vulgaris L.) Root Rot Caused by Rhizoctonia Solani in Jammu and Kashmir, India

Root rot of common bean (Phaseolus vulgaris) is one of the most serious disease, causes unadorned damage to crop health and leads to the heavy yield loss. In the present investigation, Rhizoctonia solani, a new root rot pathogen was found pathogenic and cause of beans root rot in the region of Jammu and Kashmir, India. The pathogen was characterized by morpho-cultural as well as through molecular sequencingusing ITS primer for establishing the proper identification of isolated pathogen. Based on the pathogenicity test carried on common bean cv. Shalimar Bean-1 and available literature, it was recorded as the first report of root rot in common beans caused by Rhizoctonia solani in Jammu and Kashmir

Morpho-Cultural and Pathogenic Variability of <i>Sclerotinia sclerotiorum</i> Causing White Mold of Common Beans in Temperate Climate

The present systematic research on cultural, morphological, and pathogenic variability was carried out on eighty isolates of Sclerotinia sclerotiorum collected from major common bean production belts of North Kashmir. The isolates were found to vary in both cultural and morphological characteristics such as colony color and type, colony diameter, number of days for sclerotia initiation, sclerotia number per plate, sclerotial weight, and size. The colony color ranged between white and off-white with the majority. The colony was of three types, in majority smooth, some fluffy, and a few fluffy-at-center-only. Colony diameter ranged between 15.33 mm and 29 mm after 24 h of incubation. The isolates took 4 to 7 days for initiation of sclerotia and varied in size, weight, and number per plate ranging between 14 and 51.3. The sclerotial arrangement pattern on plates was peripheral, sub peripheral, peripheral, and subperipheral, arranged at the rim and scattered. A total of 22 Mycelial compatibility groups (MCGs) were formed with seven groups constituted by a single isolate. The isolates within MCGs were mostly at par with each other. The six isolates representing six MCGs showed variability in pathogenicity with isolate G04 as the most and B01 as the least virulent. The colony diameter and disease scores were positively correlated. Sclerotia were observed to germinate both myceliogenically and carpogenically under natural temperate conditions of Kashmir. Germplasm screening revealed a single resistant line and eleven partially resistant lines against most virulent isolates

Sustainable Management of Green Mold Disease of White Button Mushroom Using Botanicals and Biocontrol Agents under Temperate Conditions

Green mold (caused by Trichoderma harzianum) is a destructive disease in mushrooms which limits commercial production. The present investigation was carried out to verify the in vitro and in vivo effect of locally available botanicals and bacterial biocontrol agents against this disease. The in vitro evaluation of ethanol extract of botanicals against mycelial growth of T. harzianum at 1, 2, and 3% concentrations showed that Juglans regia and Allium sativum exhibited maximum mycelial growth inhibition of 84.9 and 79.8%, respectively. When the same botanicals were tested against the mycelial growth of A. bisporus, it was observed that J. regia, Curcuma longa, and Azadirachta mellea were least inhibitory (4.66–7.4%). From the in vivo evaluation of plant botanicals at 2% concentration, J. regia and C. longa had the highest average weight (11.8–11.9 g) of a single fruit body and a combined button yield of 11.3–11.9 kg/quintal compost. Among the bacterial bioagents evaluated in vitro, Pseudomonas flourescens, Azotobacter sp., and Bacillus subtilis displayed stimulatory effects of varying degrees on the mycelial growth of A. bisporus but exhibited antagonistic effects on T. harzianum. B. subtilis-38, and P. flourescens-104. Azotobacter-108 caused the highest mycelial growth inhibition of 97.6, 97.4, and 90.3% of T. harzianum, respectively. The current study reveals that the integration of botanical and bacterial antagonists in pathogen-infested white button mushroom casing reduces green mold infection with corresponding yield gains

Leaf Color Chart (LCC)-Based Precision Nitrogen Management for Assessing Phenology, Agrometeorological Indices and Sustainable Yield of Hybrid Maize Genotypes under Temperate Climate

Excessive nitrogenous fertilization in years resulted in larger nitrogen and profit losses. This problem can be reduced by using need-based and time-specific nitrogen management. Therefore, a field experiment was carried out during the Kharif season of 2019 and 2020 in order to evaluate the impact of precision nitrogen management on the phenology, yield and agrometeorological indices of hybrid maize genotypes at the Agronomy Research Farm, FoA Wadura, Sopore, SKUAST-Kashmir. The experiment was carried out in split-plot design consisting of maize hybrids (Shalimar Maize Hybrid-2 Vivek-45 and Kanchan-517) as main plot treatments and precision nitrogen management (T1: Control, T2: Recommended N, T3: 25% N as basal ≤ LCC 3@20 kg N ha−1, T4: 25% N as basal ≤ LCC 3@30 kg N ha−1, T5: 25% N as basal ≤ LCC 4@20 kg N ha−1, T6: 25% N as basal ≤ LCC 4@30 kg N ha−1, T7: 25% N as basal ≤ LCC 5@20 kg N ha−1 and T8: 25% N as basal ≤ LCC 5@30 kg N ha−1) as sub-plot treatments. Results demonstrated that maize hybrids showed a non-significant difference in attaining different phenophases during both years. However, Shalimar Maize Hybrid-2 demonstrated higher grain (62.35 and 60.65 q ha−1) and biological yield (170.26 and 165.86 q ha−1), a higher number of days to attain different phenological stages in comparison to Vivek-45 and Kanchan-517 thereby achieved higher heat units, PTUs, HTUs, PTI. The application of nitrogen through LCC ≤ 5@30 kg N ha−1 noted higher grain yield (61.27 and 59.13 q ha−1) and biological yield (171.30 and 166.13 q ha−1) during 2019 and 2020 respectively. Higher values of Growing degree days (GDD), Heliothermal units (HTU), Photothermal units (PTU), Phenothermal index (PTI), heat use efficiency (HUE) and radiation use efficiency (RUE) were observed in the application of nitrogen through LCC ≤ 5@30 kg N ha−1 and required the highest number of days to reach different phenophases than other treatments during crop growing seasons of 2019 and 2020. The results demonstrated that Nitrogen application based on LCC ≤ 5@30 proved effective and should be adopted in maize hybrids especially in Shalimar Maize Hybrid-2 to attain higher yield under the temperate climate of Kashmir Valley

Comparative Analysis of Rice and Weeds and Their Nutrient Partitioning under Various Establishment Methods and Weed Management Practices in Temperate Environment

A research trial was conducted at Agronomy Farm (SKUAST-K, Wadura, Jammu & Kashmir), during kharif 2017 and 2018 to evaluate nutrient removal in rice under various rice establishment methods and weed control measures. The study comprised of two factors: rice establishment techniques {Transplanting (TPR); Direct seeding (DSR) and System of rice intensification (SRI)} as main plot treatments and weed control measures {Butachlor @ 1500 g a.i ha−1 (B); Penoxsulam @ 22.5 g a.i ha−1 (P); Pyrazosulfuron ethyl + Pretilachlor @ 15 and 600 g a.i ha−1 (PP); Bensulfuron methyl + Pretilachlor @ 60 and 600 g a.i ha−1 (BP); 2 Conoweeding/Hand Weeding (CW/HW); Weed free (WF) and weedy check (WC)} as sub-plot treatments meant to evaluate the best establishment method and weed management practice for rice. Over DSR and transplanted rice, the SRI technique yielded a significant increase in dry biomass accumulation (17.04 and 17.20 t ha−1) and grain (7.92 and 8.17 t ha−1) and straw (9.60 and 10.17 t ha−1) yields. Penoxsulam herbicide significantly showed higher grain and straw yield of 8.19 and 8.28 t ha−1 and 10.13 and 10.44 t ha−1, respectively, than other weed management measures by comparing the means using critical difference. TPR excelled in reducing dry weed biomass more than other established methods. All herbicides considerably reduced dry weed biomass, but Penoxsulam herbicide showed the greatest reduction in dry weed biomass and proved superior against complex weed flora. Weeds showed maximum contribution towards total Biomass under DSR, among rice establishment techniques. In contrast, among different weed control measures, it was maximum in weedy check treatment (Untreated Control) and minimum in penoxsulam treatment. SRI significantly excelled in crop (grain and straw) nutrient uptake compared to the DSR and TPR method, although different crop establishment techniques non-significantly influenced nutrient concentrations. Furthermore, penoxsulam treatment demonstrated higher crop (grain and straw) nutrient uptake among the various weed management measures. However, available soil nutrients were observed among establishment techniques, highest in DSR and lowest in SRI. Moreover, direct-seeded rice excelled SRI and transplanted rice in weed nutrient uptake, and among the different herbicidal treatments, penoxsulam recorded the lowest uptake in weeds. Nutrient budgeting demonstrated that DSR showed the maximum percentage of nutrient removal by weeds, and the minimum ratio was in TPR. In contrast, the lowest rate of nutrients removed via weeds were seen in penoxsulam application under various weed management measures

Real-Time Nitrogen Application of Rice Varieties Based on Leaf Colour Chart under System of Rice Intensification in Temperate Climate

Increasing nitrogen use efficiency in rice intensification (SRI) is pivotal to achieving high crop yield and reducing nitrogen losses. To find the critical value of the leaf color chart (LCC) for real-time nitrogen (N) application in rice varieties under SRI, a field experiment was laid at the Research Farm, Faculty of Agriculture, Wadura, SKAUST-Kashmir in Kharif between 2019 and 2020. The experiment comprised two cultivars (SR-3 and SR-4) and eight LCC-based nitrogen managements (control, recommended dose of nitrogen (RDF), and three LCC scores (≤3, ≤4, ≤5 each with 20 and 30 kg N ha−1). SR-4 produced significantly higher values for growth and yield parameters, producing higher grain yield (7.02 and 6.86 t ha−1) compared to SR-3 (6.49 and 6.36 t ha−1) between 2019 and 2020, respectively. An LCC value of 5 with 30 kg N ha−1 produced maximum grain yield (7.84 and 7.70 t ha−1) in 2019 and 2020, respectively, which were statistically at par with the LCC value of 5 with 20 kg Nha−1. Pooled data revealed that the highest B: C ratio of 1.55 was recorded in cultivar SR-4 with an LCC value of 5 with 30 kg N ha−1. Furthermore, agronomic and recovery efficiency of nitrogen remained maximum in LCC 5 with 20 kg N ha−1 for both years. Grain yield recorded in LCC 3 20 kg N ha−1 was similar to recommended nitrogen. The present study highlighted the need-based N application through LCC and proved effective in increasing the N-use efficiency and yield in rice

Management of Green Mold Disease in White Button Mushroom (Agaricus bisporus) and Its Yield Improvement

Mycoparasites cause serious losses in profitable mushroom farms worldwide. The negative impact of green mold (Trichoderma harzianum) reduces cropping surface and damages basidiomes, limiting production and harvest quality. The goal of the current study was to evaluate new generation fungicides, to devise suitable management strategies against the green mold disease under prevailing agro-climatic conditions. Six non-systemic and five systemic fungitoxicants were evaluated for their efficacy against pathogen, T. harzianum, and host, Agaricus bisporus, under in vitro conditions. Among non-systemic fungicides, chlorothalonil and prochloraz manganese with mean mycelium inhibition of 76.87 and 93.40 percent, respectively, were highly inhibitory against the pathogen. The least inhibition percentage of 7.16 of A. bisporus was exhibited by chlorothalonil. Under in vivo conditions, use of captan 50 WP resulted in a maximum yield of button mushroom of 14.96 kg/qt. So far, systemic fungicides were concerned, carbendazim proved extremely inhibitory to the pathogen (89.22%), with least inhibitory effect on host mycelium (1.56%). However, application of non-systemic fungitoxicants further revealed that fungicide prochloraz manganese 50 WP at 0.1&ndash;0.2 percent or chlorothalonil 50 WP at 0.2 percent, exhibited maximum disease control of 89.06&ndash;96.30 percent. Moreover, the results of systemic fungitoxicants showed that carbendazim 50 WP or thiophanate methyl 70 WP at 0.1 percent reduced disease to 2.29&ndash;3.69 percent, hence exhibiting the disease control of 80.11&ndash;87.66 percent. Under in vivo conditions, fungicide myclobutanil at 0.1 percent concentration produced the maximum button mushroom production of 12.87 kg/q