VARIABILITY AND GENETIC PARAMETERS FOR GRAIN YIELD AND ITS COMPONENTS AND KERNEL QUALITY ATTRIBURTES IN CMS BASED RICE HYBRIDS (ORYZA SATIVA L.)
The present investigation was under taken to study the extent of variability and genetic parameters with 16 parents and 48 hybrids for nine yield and its components and twenty five quality characters. The magnitude of difference between PCV and GCV was relatively low for all the traits, indicating less environmental influence. High GCV and PCV were recorded for harvest index, total number of productive tillers per plant and gelatinization temperature in parents and for total number of productive tillers per plant, number of grains per panicle, gelatinization temperature and amylose content in hybrids. High heritability coupled with high genetic advance as per cent of mean were recorded for gelatinization temperature, harvest index, total number of productive tillers per plant, number of grains per panicle, kernel length, kernel L/B ratio and grain yield per plant in case of parents and for gelatinization temperature, amylose content, total number of productive tillers per plant, number of grains per panicle and harvest index in case of hybrids indicating the additive gene effects in the genetic control of these traits and can be improved by simple selection in the present breeding material.
Genetics of wide compatible gene and variability studies in rice (Oryza sativa L.)
Hybrid rice technology offers great potential to increase rice production and productivity on a sustainable basis. Exploitation of heterosis in rice has resulted in release of several hybrids for commercial cultivation in India. One of the current aspects of hybrid rice breeding is exploitation of higher degree of heterosis in intervarietal crosses (indica/japonica) over the intravarietal crosses (indica × indica, japonica × japonica and javanica × javanica). Wide compatibility (WC) is one of the most important traits in rice which can overcome the fertility barrier in the indica/japonica hybrids. The S5n gene located on chromosome 6 is responsible for the WC in rice (Yang et al. 2009). Hence, understanding the inheritance pattern of WC gene is critical to choose the suitable breeding method to be followed for breaking the sterility barrier between indica and japonica. Quantum jump in yield improvement has been achieved in rice with the development of high yield heterotic hybrids under commercial cultivation. However, rice being the staple food of Indians, improving its productivity has become a critically important issue (Subbaiah et al. 2011). Knowledge on the nature and magnitude of genetic variation governing the inheritance of quantitative characters, such as yield and its components are essential for effecting genetic improvement. A critical analysis of genetic variability is necessary for initiating any crop improvement programme and for adopting appropriate selection techniques. To develop high yielding genotypes coupled with good grain quality, and resistance to pest and diseases, population with high genetic variability serves as prime source for effective selection, particularly the F2 population. F2 generations are the critical stage
Cytoreductive Surgery Plus Hyperthermic Intraperitoneal Chemotherapy for Pseudomyxoma Peritonei Arising from Urachus
BackgroundPseudomyxoma peritonei (PMP) is a rare locoregional disease characterized by disseminated intraperitoneal mucinous tumors. However, little is known about PMP from urachal neoplasm as a result of its rarity.MethodsA total of 9 patients with PMP of urachal origin were treated by cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) in our institution. All specimens of surgeries were submitted for pathologic examination. Representative slides of tumors and normal urachus were submitted for immunohistochemical staining.ResultsFour patients were men; the median age was 48 years (range 27–65 years). Initial radiologic examination of all patients showed a cystic tumor located between posterior aspect of umbilicus and the dome of urinary bladder, with or without leaking mucin. Complete CRS and HIPEC were performed in all patients. Until the latest follow-up, local recurrence occurred in 1 patient. Other 8 patients had a median disease-free survival of 27.5 months. Primary urachal tumors of 9 cases were all mucinous adenocarcinoma. Six patients had low-grade mucinous carcinoma peritonei, and 3 patients had high-grade mucinous carcinoma peritonei. Signet ring cells were noted in 4 patients. All tumor specimens of 9 patients were diffuse positive for CK-20, CDX-2, MUC-2, and MUC-5AC, and were variant positive for CK-7.ConclusionsPMP arising from urachus comes from neoplastic cells with development of intestinal-type mucinous neoplasm. It shares a similar pathophysiology as PMP from appendix. CRS including total urethrectomy, partial cystectomy, and peritonectomy plus HIPEC can be considered as a new option of treatment for PMP originating from urachus.