Mapping and marker-assisted breeding of a gene allelic to the major Asian rice gall midge resistance gene Gm8

Host plant resistance is the preferred management strategy for Asian rice gall midge (Orseolia oryzae), a serious pest in many rice-growing countries. Identification of simple sequence repeat (SSR) markers that are tightly linked to pest resistance genes can accelerate development of gene pyramids for durable/multiple resistance. Based on conventional and molecular allelism tests, we report herein that rice genotype Aganni possesses Gm8 gene, conferring hypersensitive independent (HR– type) resistance to gall midge biotypes GMB1, GMB2, GMB3, GMB4, and GMB4M. The gene Gm8 was mapped to chromosome 8 within a 400-kbp region, and the SSR markers RM22685 and RM22709 flank the gene closely. Using these closely linked flanking markers, nine other gall midge-resistant genotypes were identified as carrying the same gene Gm8. Through marker-assisted selection, Gm8 has been introgressed into an elite bacterial blight-resistant cultivar, Improved Samba-Mahsuri (IS

Improvement of two traditional Basmati rice varieties for bacterial blight resistance and plant stature through morphological and marker-assisted selection

Bacterial blight (BB) is a major production threat to Basmati, the aromatic rice prized for its unique quality. In order to improve the BB resistance of two elite, traditional BB-susceptible Basmati varieties (Taraori Basmati and Basmati 386), we utilized the strategy of limited marker-assisted backcrossing for introgression of two major BB resistance genes, Xa21 and xa13, coupled with phenotype-based selection for improvement of their plant type and yield. Improved Samba Mahsuri, an elite high-yielding, fine-grain-type BB-resistant rice variety served as donor for BB resistance. Backcross-derived improved Basmati lines at BC1F5 possessing a single resistance gene (i.e. either Xa21 or xa13) displayed moderate resistance to BB, while lines possessing both Xa21 and xa13 showed significantly higher levels of resistance. Two-gene pyramid lines (Xa21 + xa13) possessing good grain and cooking quality similar to their respective traditional Basmati parents, short plant stature (<110 cm plant height) and higher grain yield than the recurrent parent(s) were identified and advanced. This work demonstrates the successful application of marker-assisted selection in conjunction with phenotype-based selection for targeted introgression of multiple resistance genes into traditional Basmati varieties along with improvement of their plant stature and yield

Assessment of different methods of rice (Oryza sativa. L) cultivation affecting growth parameters, soil chemical, biological, and microbiological properties, water saving, and grain yield in rice–rice system

Field experiments were conducted at DRR farm located at ICRISAT, Patancheru, in sandy clay loam soils during four seasons, Kharif 2008, Rabi 2008–2009, Kharif 2009 and Rabi 2009–2010, to investigate growth parameters, water-saving potential, root characteristics, chemical, biological, and microbial properties of rhizosphere soil, and grain yield of rice (Oryza sativa L.) by comparing the plants grown with system of rice intensification (SRI) methods, with organic or organic + inorganic fertilization, against current recommended best management practices (BMP). All the growth parameters including plant height, effective tillers (10–45 %), panicle length, dry matter, root dry weight (24–57 %), and root volume (10–66 %) were found to be significantly higher with in SRI-organic + inorganic over BMP. With SRI-organic fertilization, growth parameters showed inconsistent results; however, root dry weight (3–77 %) and root volume (31–162 %) were found significantly superior compared to BMP. Grain yield was found significantly higher in SRI-organic + inorganic (12–23 and 4–35 % in the Kharif and Rabi seasons, respectively), while with SRI-organic management, yield was found higher (4–34 %) only in the Rabi seasons compared to BMP. An average of 31 and 37 % of irrigation water were saved during Kharif and Rabi seasons, respectively, with both SRI methods of rice cultivation compared to BMP. Further, total nitrogen, organic carbon%, soil dehydrogenase, microbial biomass carbon, total bacteria, fungi, and actinomycetes were found higher in the two SRI plots in comparison to BMP. It is concluded that SRI practices create favorable conditions for beneficial soil microbes to prosper, save irrigation water, and increase grain yield

SRI-A Method for Sustainable Intensification of Rice Production with Enhanced Water Productivity

Climate change induced higher temperatures will increase crops’ water requirements. Every 10°C increase in mean temperature, results in 7% decline in the yield of rice crop. Hence, there is a need to develop water saving technologies in rice which consumes more than 50% of the total irrigation water in agriculture. System of Rice Intensification (SRI) is one such water saving rice production technology. Experiments were conducted at different locations in India including research farm of Directorate of Rice Research (DRR), Hyderabad, during 2005-10 to assess the potential of SRI in comparison to normal transplanting/Standard Planting (NTP/SP) under flooded condition. SRI recorded higher grain yield (6 to 65% over NTP) at majority of locations. Long term studies clearly indicated that grain yield was significantly higher (12-23% and 4-35% over NTP in Kharif and Rabi seasons, respectively) in SRI (with organic+inorganic fertilizers) while the SRI (with100% organic manures), recorded higher yield (4-34%) over NTP only in the Rabi seasons. Even though, SRI resulted in higher productivity, the available nutrient status in soil was marginally higher (10, 42 and 13% over NTP for N, P and K, respectively) at the end of four seasons. There was a reduction in the incidence of pests in SRI and the relative abundance of plant parasitic nematodes was low in SRI as compared to the NTP. About 31% and 37% saving in irrigation water was observed during Kharif and Rabi seasons, respectively in both methods of SRI cultivation over NTP. SRI performed well and consistently reduced requirement of inputs such as seed and water in different soil conditions. SRI method, using less water for rice production can help in overcoming water shortage in future and it can also make water available for growing other crops thus promoting crop diversificatio

Gessius verticalis Distant

Gessius verticalis Distant Figs 1–19 Gessius verticalis Distant 1908: 302, Fig. 192. Type Ψ, Burma: Ruby mines [BMNH, examined]. Coloration dark green in life, preserved specimens blackish green to reddish brown. Dark green specimens with paler spots at apex of each claval vein. Forewing with brownish suffusion on clavus continued to apex. Veins margined by circular pits, those bordering claval veins more dense. Male eighth sternite large, hind margin medially slightly convex, devoid of setae. Male genitalia: Pygophore lobe with membranous unpigmented area in form of vertical band at point of connection to anal segment, covered with stout setae; ventral process more or less S-shaped, its apex sinuately curved, with narrow pointed apex, its ventral margin with one or two denticles subapically. Subgenital plate elongate, outer margin bearing hairlike setae, mesal margin with 4–5 stouter spines, these extending obliquely subapically. Aedeagus with short dorsal apodeme, long and well developed preatrium, shaft rather trowellike, shaft in lateral view of uniform width but pointed apically, its surface transversely irregularly crenulate, gonopore subapical Female genitalia: Hind margin of seventh sternite broadly excavated in middle, lateral angels rounded, setae on lateral aspect of sternite. Second pair of gonapophysis with smaller denticles between basal, middle and apical teeth. Measurements: Male 9.0 mm long, 2.3 mm wide across eyes and 2.65 mm wide across hind margin of pronotum. Female 10.6–11.3 mm long, 2.6–2.8 mm wide across eyes and 3.1–3.2 mm wide across hind margin of pronotum. Material examined: Myanmar: Type Ψ, “ Type, H.T.” (red bordered circular label) “ Gessius verticalis Dist., type ” “Ruby mines, Doherty” (both handwritten labels), “Distant Coll. 1911 - 383 ”(BMNH). Other material: 2 Ψ data as in type (IRSNB). Nepal: 1 &dcaron;, E. Nepal: Arun Valley, 15.vi. 1954, 7000 ft (2123 m), L. Swan (BMNH). India: 2 Ψ, Sikkim: Gangtok, 6.vi. 2005, C.A. Viraktamath (UAS); West Bengal: 1 specimen (abdomen missing) Kurseong, 5000 ft (1517 m), 7.ix. 1909, N. Annandale (ZSI). Remarks: The two females from Sikkim are very dark green in life and were collected on a shrub bordering a narrow stream of water on a steep slope. The females from Ruby mines including the type are reddish brown; the male is more ochraceous brown. Two males of an undescribed species of Gessius from Formosa (Taiwan) were also examined. Darker spots described by Distant (1908) on the scutellum were not found in the type specimen examined.Published as part of Viraktamath, C. A., 2006, Revision of the leafhopper tribe Krisnini (Hemiptera: Cicadellidae: Iassinae) of the Indian subcontinent, pp. 1-32 in Zootaxa 1338 on pages 5-8, DOI: 10.5281/zenodo.17433

Krisna burmanica Viraktamath, 2006, sp. nov.

Krisna burmanica sp. nov. Figs 47–51 Pale stramineous. Anterior margin of head, clavus at base pale brown, no fuscous spot at base of appendix. No prominent apodemes on any of abdominal segment. Male genitalia: Ventral pygophore process in lateral view sinuate, with small tooth at midlength and a few more before subapical expansion, spicules in basal half of expansion fewer in number than in K. megha sp. nov. (see below), apically with ridges. Apex of apophysis of style of type 1. Aedeagal shaft short and stout, preatrium short, ventral margin of aedeagal shaft in lateral view rounded, with distinct ventral concavity at mid region, in caudal view, widened near midlength, before slightly narrowing towards apex. Measurements: Male 9.7 mm long, 2.2 mm wide across eyes, 2.7 mm wide across hind margin of pronotum. Material examined: Holotype &dcaron;, Myanmar: Upper Burma: Seinghku Valley, Nogmune, 28 ° 5 ’ N, 97 ° 25 ’ E, 1500 m, 22.iv. 1926, F. Kingdon Ward (BMNH). Remarks: K. burmanica is peculiar in not having any prominent abdominal apodemes on any of the abdominal segments. It shares the character of spiculate ventral process of male pygophore with K. megha sp. nov. (see below) but differs from it in having fewer spicules, and these are restricted to the basal half of the subapical expansion only. The aedeagus of K. burmanica has a slightly more sinuate hind margin than in K. megha where it is almost straight.Published as part of Viraktamath, C. A., 2006, Revision of the leafhopper tribe Krisnini (Hemiptera: Cicadellidae: Iassinae) of the Indian subcontinent, pp. 1-32 in Zootaxa 1338 on page 15, DOI: 10.5281/zenodo.17433

Krisna megha Viraktamath, 2006, sp. nov.

Krisna megha sp. nov. Figs 23, 27, 33, 65– 71 Pale green, anterior margin of head pale reddish brown, spot at base of forewing appendix piceous. Fore tibiae, tarsi pale reddish brown. Slender species. Head slightly longer medially than next to eyes, fore margin reflexed with 3 continuous carinae above ocelli, 8–9 carinae below ocelli on face on ocellocular area. Upper part of frontoclypeus depressed with lateral several incomplete and dorsal 6–7 complete striae, rest of frontoclypeus rough textured. Clypeus with median ridge in basal half. Pronotum more than 5 times as long as head, slightly wider than long, scutellum longer than pronotum. Claval area coarsely pitted along margin and veins with 1 or 2 rows in the claval cell area, corium pitted along veins. Costal area more heavily pitted in basal half. Abdominal segments without prominent apodemes. Male eighth sternite about as long as broad with rounded outer distal angles, hind margin straight, with setae confined to median area, lateral area with hairlike setae. Male genitalia: Pygophore with ventral process fusiform near apex, surface adorned with sevaral spicules in apical half but spicules not extend beyond basal half of fusiform apical region. Subgenital plate with rounded inner angle. Style curved near distal end and of type 1. Connective and style of typical type. Aedeagus stout with corrugated ventral lower margin distal half of shaft tapered both in lateral and caudal aspects. Female genitalia: Seventh sternite rather rectangular, hind margin medially slightly produced, bisinuate with median shallow concavity. Second pair of gonapophysis with several smaller teeth between distal two teeth, also beyond distal prominent tooth, ventral margin with subapical notch. Measurements: Male 8.67 (8.50 –9.00) mm long, 2.15 (2.10 – 2.20) mm wide across eyes, 2.46 (2.40–2.60) mm wide across hind margin of pronotum. Female 9.80 (9.50–10.10) mm long, 2.40 (2.40–2.50) mm wide across eyes, 2.75 (2.70–2.80) mm wide across hind margin of pronotum. Material examined: Holotype &dcaron;, India: Meghalaya: Cherrapunji, 1299m, 5.xi. 1981, C.A. Viraktamath (UAS). Paratypes: 2 &dcaron;, 2 Ψ, data as for holotype; 3 &dcaron;, 1 Ψ, data as for holotype but collected by S. Viraktamath; 1 &dcaron;, 1 Ψ India: Assam: Shillong, x. 1981 C. A. Viraktamath; 1 &dcaron;, India: Meghalaya: Mawsmi Cave, 1200 m, 25.ii. 1991, I. Dworakowska (BMNH, IARI, UAS, USNM). Remarks: The male from Mawsmi Cave is a teneral specimen with a red transverse band, interrupted in the middle, on the fore margin of the head. This species is peculiar in having a spiculate ventral process of the pygophore a character it shares with K. burmanica. It differs from K. burmanica in the shape of the aedeagus. It is also the most slender species of Krisna on the subcontinent.Published as part of Viraktamath, C. A., 2006, Revision of the leafhopper tribe Krisnini (Hemiptera: Cicadellidae: Iassinae) of the Indian subcontinent, pp. 1-32 in Zootaxa 1338 on page 20, DOI: 10.5281/zenodo.17433

Krisna strigicollis Spinola

Krisna strigicollis (Spinola) Figs 21, 29, 34, 80– 87 Siva strigicollis Spinola 1850: 128. Type sex? India: Coromandal [not examined] Krisna strigicollis (Spinola): Kirkaldy 1900: 243; Distant 1908: 297, Fig. 189. Green with a reddish brown to black marginal spot on head, medially interrupted where it enlarges into larger spot; in some specimens seen as black spot on either side of median line. Head medially longer than next to eyes, fore margin distinctly rimmed, surface on rim rugose with a strong carina dorsally, another less prominent carina on lower margin, disc of vertex transversely wrinkled, frontoclypeus depressed beneath rim, roughly sculptured, 4–5 carinae below ocelli on ocellocular area. Ocellus almost contiguous with adjacent eye. Pronotum about 2.5 times as long as vertex, about as long as or slightly shorter than scutellum. Abdominal tergites without apodemes, apodemes of abdominal sternite 3 very well developed reaching posterior margin of 2 nd abdominal segment, diverging, each apodeme both laterally and mesally concave with much longer lateral extension distally. Apodemes of male abdominal segment 4 well developed, broader than long, medially rather contiguous. Male eighth sternite broader than long, with hind margin medially concave lateral angles rounded, entire area in apical half covered sparsely with setae. Male genitalia: Ventral pygophore process enlarged at distal 0.33 then tapered asymmetrically, distal half of enlarged area longitudinally rugose. Subgenital plate with Vshaped excavation near proximal area on mesal margin. Style with apophysis of type 2. Aedeagus robust, broadest at midlength, gonopore visible as a tube between 2 margins of trough formed by concavity of aedeagal shaft on ventral margin, dorsal margin with rough sculpturing in C-shaped concavity, in lateral aspect apical 0.33 of shaft much narrower. Female genitalia: Hind margin of seventh sternite slightly concave medially, with rounded lateral angles. Second pair of gonapophysis with undulated margin between distal 2 prominent teeth, also on margin beyond distal prominent tooth, ventral margin with subapical notch, dorsal margin before proximal prominent tooth serrated for short distance. Measurements: Male 10.17 (9.50–11.60) mm long, 2.60 mm wide across eyes, 3.30 (3.20–3.60) mm wide across hind margin of pronotum. Female 11.60 (10.90–12.30) mm long, 2.90 mm wide across eyes, 3.70 (3.60–5.90) mm wide across hind margin of pronotum. Material examined: India: West Bengal: 2 &dcaron;, 3 Ψ, Calcutta, 22.xi. 1981; 1 &dcaron;, Kalimpong, 1780 m, 6.vi. 2005; Karnataka: 1 Ψ, Mudigere, 5.vi. 1979; Kerala: 1 &dcaron;, Maraiyur, 1066 m, 24.iii. 1977, all collected by C.A. Viraktamath; Trichur: Mannuthy, 25.xi. 1976, at light, G. Mathew; 1 Ψ, Walayar, 26.x. 1975, C. A. Viraktamath; Malabar: Walayar forest, 1000ft (303 m), vi. 1957, P.S. Nathan (IRSNB); India: Neerlandaiser, Suyoscerbuyk (IRSNB). Nepal: 1 Ψ, near Birganj, Lothar, 450 ft (137 m), 9.ix. 1967, Canadian Nepal Expedition (CNC). Remarks: Specimens from Thailand (2 Ψ, IRSNB) and Philippines (1 &dcaron;, 1 Ψ) were also examined during the study. All specimens studied have two black transverse spots on the anterior margin of the head. Males also possess prominent basal abdominal apodemes. Selenocephalus costalis Stål (1859: 290) from Malay Peninsula, currently a junior synonym of this species, is probably a species distinct from K. strigicollis. The anterior rim of its head is very similar to that of K. magna Baker (Fig. 20). In K. magna the rim and vertex do not bear any striae, but these are present in K. strigicollis. K. magna is also very robust and has a more strongly arched pronotum than does K. strigicollis. Another current synonym of K. strigicollis is K. stramineus Walker. The female type of the latter species (BMNH, figured by Distant, 1908, fig. 189) matches K. strigicollis but is labeled from Java. However, examination of numerous specimens from the Pacific by M.D. Webb (BMNH) has revealed no further matching specimens, e.g. with two spots on the forehead. It is concluded therefore, that this may be a mislabeled specimen. The male genitalia of a specimen from Java was figured as K. strigicollis by Linnavuori and Quartau (1975, fig. 100 a–d), but the aedeagus does not match the specimens figured here and it is concluded that this is a misidentification. Also, in the same paper the figure of K. kirbyi (fig. 100 e), without locality data, appears to be that of K. varia. This species resembles K. bakeri and can be easily recognized by the spots on the forehead, ocelli being very close or contiguous with the adjacent eyes, and the strongly developed abdominal apodemes in addition to the structure of the aedeagus and the apex of the apophysis of the style. From K. bakeri it differs in the shape of the aedeagus, style, and abdominal apodemes; the ventral margin of aedeagus is uniformly curved in K. bakeri whereas it is slightly concave at midlength in K. strigicollis.Published as part of Viraktamath, C. A., 2006, Revision of the leafhopper tribe Krisnini (Hemiptera: Cicadellidae: Iassinae) of the Indian subcontinent, pp. 1-32 in Zootaxa 1338 on pages 24-26, DOI: 10.5281/zenodo.17433

Krisna bakeri Viraktamath, 2006, sp. nov.

Krisna bakeri sp. nov. Figs 22, 30, 32, 36– 46 Green to greenish ochraceous with red tinge. Vertex with rounded anterior margin between eyes, medially slightly longer than next to eyes. Frons slightly depressed beneath anterior margin with coarse sculpturing. Hind wings milky white. Male abdominal terga 2, 3 and 4 with apodemes (Figs 38–40). Male eighth sternite widened in distal half, lateral angles of hind margin rounded, caudal margin almost straight with several spines on ventral surface. Male genitalia: Ventral pygophore process broad in basal 0.33, narrowed and of uniform width in middle 0.33, then broadened gradually and narrowed to pointed apex, apical area with a few longitudinal rugae, dorsal margin of process in some specimens serrated at midlength. Style of type 1. Aedeagus with preatrium well developed, shaft broadest at basal 0.25, then narrowed to apex, ventral margin rather straight, dorsal margin concave, with serrated margin, short rugae, and denticles. Female genitalia: Hind margin of seventh sternite broader than long, rather rectangular, hind margin slightly produced in middle. Second pair of gonapophysis with smooth area between distal and middle teeth, apex rather broadly rounded, without subapical ventral notch. Measurements: Male 10.40 mm long (10.30–10.70 ), 2.55 mm wide across eyes, 3.15 (3.10–3.30) mm wide across hind margin of pronotum. Female 11.40 mm long, 2.70 mm wide across eyes, 3.30 mm wide across hind margin of pronotum. Material examined: Nepal: Holotype &dcaron;, Katmandu, 12.vi. 1978, V.K. Thapa (UAS). Paratypes: Nepal: 3 &dcaron;, 1 Ψ, data as for holotype (BMNH, IARI, UAS); 3 Ψ, Katmandu, Kokari-Takha, 28.x- 14.xi. 1978, V.K. Thapa (UAS); 14 &dcaron;, 1 Ψ, near Simra, Adhobhar, collected on 25 (6 &dcaron;), 27 (4 &dcaron;), 28 (4 &dcaron;, 1 Ψ), viii. 1967, Canadian Nepal Expedition; 4 &dcaron;, 1 Ψ, Katmandu: Godavari, 6000 ’ (1820 m), 15.vii (1 &dcaron;), 24.vii (1 &dcaron;), 31. vii (1 Ψ), 30.viii (2 &dcaron;), 1969, Canadian Nepal Expedition (CNC). Other material: Nepal: 4 nymphs from Bhartpur, Birganj (CNC); India: Uttaranchal: 1 &dcaron;, Dehradun, 27.iv. 1975, C.A. Viraktamath; West Bengal: 1 Ψ, 8 km E Kalimpong, 1768 m, 29.x. 1981, C.A. Viraktamath (UAS). Remarks: K. bakeri resembles K. strigicollis but in addition to differences in the male genitalia, it differs in lacking the black spots on the anterior margin of vertex, anterior rim of the head and ocelli are placed a distance more than half own diameter away from the adjacent eye; but in K. strigicollis they are much closer. The male third sternal apodemes are short and broad whereas in K. strigicollis they are widely separated, and reach anteriorly the second segment.Published as part of Viraktamath, C. A., 2006, Revision of the leafhopper tribe Krisnini (Hemiptera: Cicadellidae: Iassinae) of the Indian subcontinent, pp. 1-32 in Zootaxa 1338 on pages 11-15, DOI: 10.5281/zenodo.17433